diff --git a/P2201.cpp b/P2201.cpp
new file mode 100644
index 0000000..11d82d1
--- /dev/null
+++ b/P2201.cpp
@@ -0,0 +1,56 @@
+// 128
+#include <bits/stdc++.h>
+using namespace std;
+int q;
+int qjh[1000005];
+int ans[1000005];
+vector<int> s, tmp;
+int main()
+{
+    cin >> q;
+    for (int i = 0; i <= q + 1; ++i)
+        ans[i] = INT_MIN;
+    while (q--)
+    {
+        char c;
+        cin >> c;
+        if (c == 'I')
+        {
+            int x;
+            cin >> x;
+            s.push_back(x);
+            qjh[s.size()] = qjh[s.size() - 1] + x;
+            ans[s.size()] = max(ans[s.size() - 1], qjh[s.size()]);
+        }
+        else if (c == 'D')
+        {
+            if (!s.empty())
+                s.pop_back();
+        }
+        else if (c == 'L')
+        {
+            if (!s.empty())
+            {
+                tmp.push_back(s[s.size() - 1]);
+                s.pop_back();
+            }
+        }
+        else if (c == 'R')
+        {
+            if (!tmp.empty())
+            {
+                s.push_back(tmp[tmp.size() - 1]);
+                qjh[s.size()] = qjh[s.size() - 1] + tmp[tmp.size() - 1];
+                ans[s.size()] = max(ans[s.size() - 1], qjh[s.size()]);
+                tmp.pop_back();
+            }
+        }
+        else
+        {
+            int x;
+            cin >> x;
+            cout << ans[x] << endl;
+        }
+    }
+    return 0;
+}
\ No newline at end of file