func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 5e3 + 5;   char a[maxn], b[maxn];   int dp[maxn][maxn];   int main() {     int n, m;     cin >> n >> m;     scanf( %s%s , a + 1, b + 1);     int max_ = 0;     for (int i = 1; i <= n; ++i) {       for (int j = 1; j <= m; ++j) {         if (a[i] == b[j]) dp[i][j] = max(dp[i][j], dp[i - 1][j - 1] + 2);         dp[i][j] = max(dp[i][j], dp[i][j - 1] - 1);         dp[i][j] = max(dp[i][j], dp[i - 1][j] - 1);         max_ = max(max_, dp[i][j]);       }     }     cout << max_ << endl;     return 0;   }   