diff --git a/alstjr7437/README.md b/alstjr7437/README.md
index be196cf5..7dcd819b 100644
--- a/alstjr7437/README.md
+++ b/alstjr7437/README.md
@@ -30,4 +30,5 @@
 | 26차시 | 2024.05.22 |  정렬  | <a href="https://school.programmers.co.kr/learn/courses/30/lessons/42747">H-Index</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/196 |
 | 27차시 | 2024.05.26 |  우선순위 큐  | <a href="https://www.acmicpc.net/problem/7662">이중 우선순위 큐</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/198 |
 | 28차시 | 2024.05.30 |  브루트 포스  | <a href="https://www.acmicpc.net/problem/6064">카잉 달력</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/203 |
-| 29차시 | 2024.06.11 |  이분 탐색  | <a href="https://www.acmicpc.net/problem/2805">나무 자르기</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/210 |
\ No newline at end of file
+| 29차시 | 2024.06.11 |  이분 탐색  | <a href="https://www.acmicpc.net/problem/2805">나무 자르기</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/210 |
+| 30차시 | 2024.06.19 |  방 번호  | <a href="https://www.acmicpc.net/problem/1475">구현</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/211 |
\ No newline at end of file
diff --git "a/alstjr7437/\352\265\254\355\230\204/\353\260\251\353\262\210\355\230\270.swift" "b/alstjr7437/\352\265\254\355\230\204/\353\260\251\353\262\210\355\230\270.swift"
new file mode 100644
index 00000000..35748162
--- /dev/null
+++ "b/alstjr7437/\352\265\254\355\230\204/\353\260\251\353\262\210\355\230\270.swift"
@@ -0,0 +1,16 @@
+let N : String = readLine()!
+var result : [Character:Int] = [:]
+
+for i in N{
+    let temp = (i == "9") ? "6" : i
+    if result[temp] == nil{
+        result[temp] = 1
+    } else {
+        result[temp]! += 1
+    }
+}
+if result["6"] != nil{
+    result["6"]! = (result["6"]! + 1) / 2
+}
+
+print(result.values.max() ?? 0)
\ No newline at end of file