func_code_string: #include <bits/stdc++.h>   using namespace std;   char A[5010], B[5010];   int N, M;   int f[5010][5010];   int main() {     scanf( %d%d , &N, &M);     scanf( %s , A + 1);     scanf( %s , B + 1);     int ans = 0;     for (int i = 1; i <= N; i++) {       for (int j = 1; j <= M; j++) {         f[i][j] = max(f[i - 1][j] - 1, f[i][j - 1] - 1);         if (A[i] == B[j]) {           f[i][j] = max(f[i][j], f[i - 1][j - 1] + 2);           f[i][j] = max(f[i][j], 2);         }         ans = max(ans, f[i][j]);       }     }     cout << ans;   }   