diff --git a/yokoo_4.cpp b/yokoo_4.cpp
new file mode 100644
index 0000000..3b7de3c
--- /dev/null
+++ b/yokoo_4.cpp
@@ -0,0 +1,64 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+class Queue{
+  public:
+    int front();
+    int back();
+    void push(int set_number);
+    void pop();
+    void empty();
+    void all();
+  private:
+    vector<int> num;
+};
+
+int Queue::front()
+{
+  return num.at(0);
+}
+
+int Queue::back()
+{
+  return num.at(num.size()-1);
+}
+
+void Queue::push(int set_number)
+{
+  num.push_back(set_number);
+}
+
+void Queue::pop()
+{
+  num.erase(num.begin());
+}
+
+void Queue::empty()
+{
+  cout << num.size() << endl;
+}
+void Queue::all()
+{
+  for(int i=0;i<num.size();i++){
+    cout << num.at(i) << " ";
+  }
+  cout << endl;
+}
+
+int main(){
+  Queue queue;
+  for(int i=0;i<10;i++){
+    queue.push(i*3);
+  }
+  queue.all();
+  for(int i=0;i<10;i++){
+    queue.pop();
+  }
+  queue.empty();
+
+  return 0;
+}
+
+