diff --git a/src/euler/p096/data.cljc b/src/euler/p096/data.cljc
new file mode 100755
index 0000000..8e80227
--- /dev/null
+++ b/src/euler/p096/data.cljc
@@ -0,0 +1,506 @@
+(ns euler.p096.data)
+
+(def input
+  ["Grid 01"
+   "003020600"
+   "900305001"
+   "001806400"
+   "008102900"
+   "700000008"
+   "006708200"
+   "002609500"
+   "800203009"
+   "005010300"
+   "Grid 02"
+   "200080300"
+   "060070084"
+   "030500209"
+   "000105408"
+   "000000000"
+   "402706000"
+   "301007040"
+   "720040060"
+   "004010003"
+   "Grid 03"
+   "000000907"
+   "000420180"
+   "000705026"
+   "100904000"
+   "050000040"
+   "000507009"
+   "920108000"
+   "034059000"
+   "507000000"
+   "Grid 04"
+   "030050040"
+   "008010500"
+   "460000012"
+   "070502080"
+   "000603000"
+   "040109030"
+   "250000098"
+   "001020600"
+   "080060020"
+   "Grid 05"
+   "020810740"
+   "700003100"
+   "090002805"
+   "009040087"
+   "400208003"
+   "160030200"
+   "302700060"
+   "005600008"
+   "076051090"
+   "Grid 06"
+   "100920000"
+   "524010000"
+   "000000070"
+   "050008102"
+   "000000000"
+   "402700090"
+   "060000000"
+   "000030945"
+   "000071006"
+   "Grid 07"
+   "043080250"
+   "600000000"
+   "000001094"
+   "900004070"
+   "000608000"
+   "010200003"
+   "820500000"
+   "000000005"
+   "034090710"
+   "Grid 08"
+   "480006902"
+   "002008001"
+   "900370060"
+   "840010200"
+   "003704100"
+   "001060049"
+   "020085007"
+   "700900600"
+   "609200018"
+   "Grid 09"
+   "000900002"
+   "050123400"
+   "030000160"
+   "908000000"
+   "070000090"
+   "000000205"
+   "091000050"
+   "007439020"
+   "400007000"
+   "Grid 10"
+   "001900003"
+   "900700160"
+   "030005007"
+   "050000009"
+   "004302600"
+   "200000070"
+   "600100030"
+   "042007006"
+   "500006800"
+   "Grid 11"
+   "000125400"
+   "008400000"
+   "420800000"
+   "030000095"
+   "060902010"
+   "510000060"
+   "000003049"
+   "000007200"
+   "001298000"
+   "Grid 12"
+   "062340750"
+   "100005600"
+   "570000040"
+   "000094800"
+   "400000006"
+   "005830000"
+   "030000091"
+   "006400007"
+   "059083260"
+   "Grid 13"
+   "300000000"
+   "005009000"
+   "200504000"
+   "020000700"
+   "160000058"
+   "704310600"
+   "000890100"
+   "000067080"
+   "000005437"
+   "Grid 14"
+   "630000000"
+   "000500008"
+   "005674000"
+   "000020000"
+   "003401020"
+   "000000345"
+   "000007004"
+   "080300902"
+   "947100080"
+   "Grid 15"
+   "000020040"
+   "008035000"
+   "000070602"
+   "031046970"
+   "200000000"
+   "000501203"
+   "049000730"
+   "000000010"
+   "800004000"
+   "Grid 16"
+   "361025900"
+   "080960010"
+   "400000057"
+   "008000471"
+   "000603000"
+   "259000800"
+   "740000005"
+   "020018060"
+   "005470329"
+   "Grid 17"
+   "050807020"
+   "600010090"
+   "702540006"
+   "070020301"
+   "504000908"
+   "103080070"
+   "900076205"
+   "060090003"
+   "080103040"
+   "Grid 18"
+   "080005000"
+   "000003457"
+   "000070809"
+   "060400903"
+   "007010500"
+   "408007020"
+   "901020000"
+   "842300000"
+   "000100080"
+   "Grid 19"
+   "003502900"
+   "000040000"
+   "106000305"
+   "900251008"
+   "070408030"
+   "800763001"
+   "308000104"
+   "000020000"
+   "005104800"
+   "Grid 20"
+   "000000000"
+   "009805100"
+   "051907420"
+   "290401065"
+   "000000000"
+   "140508093"
+   "026709580"
+   "005103600"
+   "000000000"
+   "Grid 21"
+   "020030090"
+   "000907000"
+   "900208005"
+   "004806500"
+   "607000208"
+   "003102900"
+   "800605007"
+   "000309000"
+   "030020050"
+   "Grid 22"
+   "005000006"
+   "070009020"
+   "000500107"
+   "804150000"
+   "000803000"
+   "000092805"
+   "907006000"
+   "030400010"
+   "200000600"
+   "Grid 23"
+   "040000050"
+   "001943600"
+   "009000300"
+   "600050002"
+   "103000506"
+   "800020007"
+   "005000200"
+   "002436700"
+   "030000040"
+   "Grid 24"
+   "004000000"
+   "000030002"
+   "390700080"
+   "400009001"
+   "209801307"
+   "600200008"
+   "010008053"
+   "900040000"
+   "000000800"
+   "Grid 25"
+   "360020089"
+   "000361000"
+   "000000000"
+   "803000602"
+   "400603007"
+   "607000108"
+   "000000000"
+   "000418000"
+   "970030014"
+   "Grid 26"
+   "500400060"
+   "009000800"
+   "640020000"
+   "000001008"
+   "208000501"
+   "700500000"
+   "000090084"
+   "003000600"
+   "060003002"
+   "Grid 27"
+   "007256400"
+   "400000005"
+   "010030060"
+   "000508000"
+   "008060200"
+   "000107000"
+   "030070090"
+   "200000004"
+   "006312700"
+   "Grid 28"
+   "000000000"
+   "079050180"
+   "800000007"
+   "007306800"
+   "450708096"
+   "003502700"
+   "700000005"
+   "016030420"
+   "000000000"
+   "Grid 29"
+   "030000080"
+   "009000500"
+   "007509200"
+   "700105008"
+   "020090030"
+   "900402001"
+   "004207100"
+   "002000800"
+   "070000090"
+   "Grid 30"
+   "200170603"
+   "050000100"
+   "000006079"
+   "000040700"
+   "000801000"
+   "009050000"
+   "310400000"
+   "005000060"
+   "906037002"
+   "Grid 31"
+   "000000080"
+   "800701040"
+   "040020030"
+   "374000900"
+   "000030000"
+   "005000321"
+   "010060050"
+   "050802006"
+   "080000000"
+   "Grid 32"
+   "000000085"
+   "000210009"
+   "960080100"
+   "500800016"
+   "000000000"
+   "890006007"
+   "009070052"
+   "300054000"
+   "480000000"
+   "Grid 33"
+   "608070502"
+   "050608070"
+   "002000300"
+   "500090006"
+   "040302050"
+   "800050003"
+   "005000200"
+   "010704090"
+   "409060701"
+   "Grid 34"
+   "050010040"
+   "107000602"
+   "000905000"
+   "208030501"
+   "040070020"
+   "901080406"
+   "000401000"
+   "304000709"
+   "020060010"
+   "Grid 35"
+   "053000790"
+   "009753400"
+   "100000002"
+   "090080010"
+   "000907000"
+   "080030070"
+   "500000003"
+   "007641200"
+   "061000940"
+   "Grid 36"
+   "006080300"
+   "049070250"
+   "000405000"
+   "600317004"
+   "007000800"
+   "100826009"
+   "000702000"
+   "075040190"
+   "003090600"
+   "Grid 37"
+   "005080700"
+   "700204005"
+   "320000084"
+   "060105040"
+   "008000500"
+   "070803010"
+   "450000091"
+   "600508007"
+   "003010600"
+   "Grid 38"
+   "000900800"
+   "128006400"
+   "070800060"
+   "800430007"
+   "500000009"
+   "600079008"
+   "090004010"
+   "003600284"
+   "001007000"
+   "Grid 39"
+   "000080000"
+   "270000054"
+   "095000810"
+   "009806400"
+   "020403060"
+   "006905100"
+   "017000620"
+   "460000038"
+   "000090000"
+   "Grid 40"
+   "000602000"
+   "400050001"
+   "085010620"
+   "038206710"
+   "000000000"
+   "019407350"
+   "026040530"
+   "900020007"
+   "000809000"
+   "Grid 41"
+   "000900002"
+   "050123400"
+   "030000160"
+   "908000000"
+   "070000090"
+   "000000205"
+   "091000050"
+   "007439020"
+   "400007000"
+   "Grid 42"
+   "380000000"
+   "000400785"
+   "009020300"
+   "060090000"
+   "800302009"
+   "000040070"
+   "001070500"
+   "495006000"
+   "000000092"
+   "Grid 43"
+   "000158000"
+   "002060800"
+   "030000040"
+   "027030510"
+   "000000000"
+   "046080790"
+   "050000080"
+   "004070100"
+   "000325000"
+   "Grid 44"
+   "010500200"
+   "900001000"
+   "002008030"
+   "500030007"
+   "008000500"
+   "600080004"
+   "040100700"
+   "000700006"
+   "003004050"
+   "Grid 45"
+   "080000040"
+   "000469000"
+   "400000007"
+   "005904600"
+   "070608030"
+   "008502100"
+   "900000005"
+   "000781000"
+   "060000010"
+   "Grid 46"
+   "904200007"
+   "010000000"
+   "000706500"
+   "000800090"
+   "020904060"
+   "040002000"
+   "001607000"
+   "000000030"
+   "300005702"
+   "Grid 47"
+   "000700800"
+   "006000031"
+   "040002000"
+   "024070000"
+   "010030080"
+   "000060290"
+   "000800070"
+   "860000500"
+   "002006000"
+   "Grid 48"
+   "001007090"
+   "590080001"
+   "030000080"
+   "000005800"
+   "050060020"
+   "004100000"
+   "080000030"
+   "100020079"
+   "020700400"
+   "Grid 49"
+   "000003017"
+   "015009008"
+   "060000000"
+   "100007000"
+   "009000200"
+   "000500004"
+   "000000020"
+   "500600340"
+   "340200000"
+   "Grid 50"
+   "300200000"
+   "000107000"
+   "706030500"
+   "070009080"
+   "900020004"
+   "010800050"
+   "009040301"
+   "000702000"
+   "000008006"])
+
+(def answer "26f6abfa0d7725fef678e371897d5df0")
+
diff --git a/src/euler/p096/dfuenzalida.cljc b/src/euler/p096/dfuenzalida.cljc
new file mode 100755
index 0000000..1d7fc85
--- /dev/null
+++ b/src/euler/p096/dfuenzalida.cljc
@@ -0,0 +1,94 @@
+(ns euler.p096.dfuenzalida
+  (:refer-clojure :exclude [read-string format])
+  (:require
+   [euler.utils :as u :refer [deftest md5 read-string]]
+   [euler.p096.data :refer [input answer]]
+   [clojure.test :as t :refer [is]]))
+
+(defn read-input [lines]
+  (->> lines
+       (partition 10)
+       (mapcat rest) ;; drop the lines with 'Grid NN'
+       (reduce str)
+       (map (comp read-string str)) ;; digits to numbers
+       (partition 9)
+       (partition 9)))
+
+(defn at [board x y]
+  (-> board (nth y) (nth x)))
+
+(defn column [board i]
+  (disj (->> (map #(at board i %) (range 9)) set) 0))
+
+(defn row [board j]
+  (disj (->> (map #(at board % j) (range 9)) set) 0))
+
+(defn box [board i j]
+  (let [boxi (-> i (quot 3) (* 3))
+        boxj (-> j (quot 3) (* 3))
+        xs (set (for [x (range 3) y (range 3)] (at board (+ boxi x) (+ boxj y))))]
+    (disj xs 0)))
+
+(defn valid? [board i j n] ;; is it valid to place n in the board at i, j?
+  (let [existing  (concat (column board i) (row board j) (box board i j))
+        available (reduce disj (set (range 1 10)) existing)]
+    (some? (available n))))
+
+(defn updatep [board x y n]
+  (let [xs (mapcat seq board)
+        xs (concat (take (+ x (* 9 y)) xs) [n] (drop (+ 1 x (* 9 y)) xs))]
+    (mapv vec (partition 9 xs))))
+
+(defn complete? [board] ;; not a single 0 in the board
+  (nil? (some #{0} (mapcat seq board))))
+
+(defn solve-board [board]
+  ;;  bns: possible values at bx, by, starting with 9 dummy values
+  (loop [x 0, y 0, bx -1, by -1, branching? false,
+         bns [0 0 0 0 0 0 0 0 0], board board]
+    (cond
+      (complete? board) board
+
+      ;; a whole loop without updating the board
+      (and branching?
+           (= [x y] [bx by])) (->> (map #(updatep board x y %) bns)
+                                   (map solve-board)
+                                   (remove nil?)
+                                   (filter complete?)
+                                   first)
+
+      (> x 8) (recur 0 (inc y) bx by branching? bns board)
+      (> y 8) (recur 0 0 bx by branching? bns board)
+      
+      (pos? (at board x y))
+      (recur (inc x) y bx by branching? bns board) ;; place already filled
+      :else
+      (let [existing (set (concat (column board x) (row board y) (box board x y)))
+            possible (reduce disj (set (range 1 10)) existing)]
+        (cond
+          (> (count possible) 1) (if (< (count possible) (count bns))
+                                   (recur (inc x) y x y true possible board)
+                                   (recur (inc x) y bx by true bns board))
+          (= 1 (count possible)) ;; single solution
+          (let [sol (first possible)]
+            (recur (inc x) y bx by false bns (updatep board x y sol)))
+
+          :else nil)))))
+
+(defn corner [board] ;; 3 digits on the corner of a board as a 3-digit number
+  (+ (* 100 (at board 0 0)) (* 10 (at board 1 0)) (at board 2 0)))
+
+(defn solve []
+  (->> (read-input input)
+       (map (comp corner solve-board))
+       (reduce +)))
+
+(deftest tests
+  (is (= (str answer)
+         (md5 (str (solve))))))
+
+;;;; Scratch
+
+(comment
+  (t/run-tests)
+)