diff --git a/src/10/4/P2540.cpp b/src/10/4/P2540.cpp
new file mode 100644
index 0000000..31aacab
--- /dev/null
+++ b/src/10/4/P2540.cpp
@@ -0,0 +1,168 @@
+#include <algorithm>
+#include <cstring>
+#include <iostream>
+
+int n;
+int cnts[20];
+int ans;
+
+int to_rank(int a, int b) {
+    if (a == 0)
+        return 16 + b - 1;
+    if (a == 1)
+        return 14;
+    if (a == 2)
+        return 15;
+    return a;
+}
+
+void dfs(int moves) {
+    if (moves >= ans) {
+        return;
+    }
+    bool empty = true;
+    for (int i = 3; i <= 17; ++i) {
+        if (cnts[i] > 0) {
+            empty = false;
+            break;
+        }
+    }
+    if (empty) {
+        ans = std::min(ans, moves);
+        return;
+    }
+
+    for (int len = 12; len >= 5; --len) {
+        for (int i = 3; i <= 14 - len + 1; ++i) {
+            bool pos = true;
+            for (int k = i; k < i + len; ++k) {
+                if (cnts[k] == 0) {
+                    pos = false;
+                    break;
+                }
+            }
+            if (pos) {
+                for (int k = i; k < i + len; ++k)
+                    cnts[k]--;
+                dfs(moves + 1);
+                for (int k = i; k < i + len; ++k)
+                    cnts[k]++;
+            }
+        }
+    }
+
+    for (int len = 10; len >= 3; --len) {
+        for (int i = 3; i <= 14 - len + 1; ++i) {
+            bool pos = true;
+            for (int k = i; k < i + len; ++k) {
+                if (cnts[k] < 2) {
+                    pos = false;
+                    break;
+                }
+            }
+            if (pos) {
+                for (int k = i; k < i + len; ++k)
+                    cnts[k] -= 2;
+                dfs(moves + 1);
+                for (int k = i; k < i + len; ++k)
+                    cnts[k] += 2;
+            }
+        }
+    }
+
+    for (int len = 6; len >= 2; --len) {
+        for (int i = 3; i <= 14 - len + 1; ++i) {
+            
+        }
+    }
+
+    for (int i = 3; i <= 15; ++i) {
+        if (cnts[i] >= 3) {
+            for (int k = 3; k <= 17; ++k) {
+                if (k != i && cnts[k] >= 1) {
+                    cnts[i] -= 3;
+                    cnts[k] -= 1;
+                    dfs(moves + 1);
+                    cnts[i] += 3;
+                    cnts[k] += 1;
+                }
+            }
+        }
+
+        if (cnts[i] >= 3) {
+            for (int k = 3; k <= 15; ++k) {
+                if (k != i && cnts[k] >= 2) {
+                    cnts[i] -= 3;
+                    cnts[k] -= 2;
+                    dfs(moves + 1);
+                    cnts[i] += 3;
+                    cnts[k] += 2;
+                }
+            }
+        }
+
+        if (cnts[i] >= 4) {
+            
+        }
+
+        if (cnts[i] >= 4) {
+            
+        }
+    }
+
+    if (cnts[16] > 0 && cnts[17] > 0) {
+        cnts[16]--;
+        cnts[17]--;
+        dfs(moves + 1);
+        cnts[16]++;
+        cnts[17]++;
+    }
+
+    for (int i = 3; i <= 17; ++i) {
+        if (cnts[i] >= 4) {
+            cnts[i] -= 4;
+            dfs(moves + 1);
+            cnts[i] += 4;
+        }
+        if (cnts[i] >= 3) {
+            cnts[i] -= 3;
+            dfs(moves + 1);
+            cnts[i] += 3;
+        }
+        if (cnts[i] >= 2) {
+            cnts[i] -= 2;
+            dfs(moves + 1);
+            cnts[i] += 2;
+        }
+        if (cnts[i] >= 1) {
+            cnts[i] -= 1;
+            dfs(moves + 1);
+            cnts[i] += 1;
+        }
+    }
+}
+
+void solve() {
+    std::cin >> n;
+    memset(cnts, 0, sizeof(cnts));
+    for (int i = 0; i < n; ++i) {
+        int a, b;
+        std::cin >> a >> b;
+        cnts[to_rank(a, b)]++;
+    }
+
+    ans = n;
+    dfs(0);
+    std::cout << ans << "\n";
+}
+
+int main() {
+    std::ios_base::sync_with_stdio(false);
+    std::cin.tie(NULL);
+    int T;
+    std::cin >> T >> n;
+    while (T--) {
+        solve();
+    }
+}
+// TODO to done
\ No newline at end of file