func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 1005;   int numb[MAXN], numw[MAXN];   int dp[MAXN][2];   string s[MAXN];   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     for (int i = 0; i < MAXN; i++) dp[i][0] = dp[i][1] = -1;     int n, m, x, y;     cin >> n >> m >> x >> y;     for (int i = 0; i < n; i++) cin >> s[i];     for (int t = 0; t < m; t++) {       int num = 0;       for (int i = 0; i < n; i++)         if (s[i][t] ==  # ) num++;       numb[t] = num;       numw[t] = n - num;     }     for (int t = 1; t < m; t++) numb[t] += numb[t - 1], numw[t] += numw[t - 1];     for (int t = x - 1; t < m; t++) {       for (int j = x; j <= y && t - j + 1 >= 0; j++) {         if (t - j + 1 == 0) {           if (dp[t][0] == -1) dp[t][0] = 1e9;           if (dp[t][1] == -1) dp[t][1] = 1e9;           dp[t][0] = min(dp[t][0], numb[t]);           dp[t][1] = min(dp[t][1], numw[t]);           continue;         }         if (dp[t - j][0] != -1) {           if (dp[t][1] == -1) dp[t][1] = 1e9;           dp[t][1] = min(dp[t][1], dp[t - j][0] + (numw[t] - numw[t - j]));         }         if (dp[t - j][1] != -1) {           if (dp[t][0] == -1) dp[t][0] = 1e9;           dp[t][0] = min(dp[t][0], dp[t - j][1] + (numb[t] - numb[t - j]));         }       }     }     cout << min(dp[m - 1][0], dp[m - 1][1]) <<   n ;   }   