func_code_string: #include <bits/stdc++.h>   using namespace std;   const int inf = 1e9;   int n, m;   char a[5555][5555];   int r[5555][5555];   int c[5555];   int ans = 0;   int main() {     int i, j;     cin >> n >> m;     for (i = 1; i <= n; ++i) {       getchar();       for (j = 1; j <= m; ++j) {         a[i][j] = getchar();       }     }     for (i = n; i >= 1; --i)       for (j = m; j >= 1; --j) {         if (a[i][j] ==  0 )           r[i][j] = 0;         else           r[i][j] = r[i][j + 1] + 1;       }     for (j = 1; j <= m; ++j) {       int k = 0;       for (i = 1; i <= m; ++i) {         c[i] = 0;       }       for (i = 1; i <= n; ++i) {         c[r[i][j]]++;         if (r[i][j]) k++;       }       for (i = 1; i <= m; ++i) {         if (c[i]) ans = max(ans, i * k);         k -= c[i];       }     }     cout << ans;     return 0;   }   