func_code_string: #include <bits/stdc++.h>   using namespace std;   __attribute__((constructor)) void Init() {     ios_base::sync_with_stdio(false), cin.tie(0), cout << fixed;   }   constexpr int N = 5e3;   char A[N + 2], B[N + 2];   int16_t dp[2][N + 1];   int main() {     int n, m, t = 0, ans = 0;     cin >> n >> m >> &A[1] >> &B[1];     for (int i = 1; i <= n; ++i, t = 1 - t) {       for (int j = 1; j <= m; ++j) {         int s = dp[1 - t][j - 1] + 4 * (A[i] == B[j]) - 2;         dp[t][j] = max(0, max(s, max(dp[t][j - 1], dp[1 - t][j]) - 1));         ;         ans = max<int>(ans, dp[t][j]);       }     }     cout << ans << endl;     return 0;   }   