func_code_string: #include <bits/stdc++.h>   using namespace std;   const int mod = 1e9 + 7;   const int maxn = 5e3 + 10;   int dp[maxn][maxn];   int main() {     ios::sync_with_stdio(0);     cin.tie(0);     int n, m;     cin >> n >> m;     string a, b;     cin >> a >> b;     int ans = 0;     for (int i = 1; i <= n; i++) {       for (int j = 1; j <= m; j++) {         if (a[i - 1] == b[j - 1]) {           dp[i][j] = dp[i - 1][j - 1] + 2;         } else           dp[i][j] = max({0, dp[i - 1][j] - 1, dp[i][j - 1] - 1});         ans = max(ans, dp[i][j]);       }     }     cout << ans <<   n ;   }   