func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 2020;   int Arr[N][N];   int Pre[N][N];   int Add[N][N];   bool Col[N];   bool Row[N];   int getSum(int x1, int y1, int x2, int y2) {     return Pre[x2][y2] - Pre[x1 - 1][y2] - Pre[x2][y1 - 1] + Pre[x1 - 1][y1 - 1];   }   int main() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int n;     cin >> n;     int k;     cin >> k;     for (int i = 1; i <= n; i++)       for (int j = 1; j <= n; j++) {         char ch;         cin >> ch;         Arr[i][j] = (ch ==  B );       }     for (int i = 1; i <= n; i++)       for (int j = 1; j <= n; j++)         Pre[i][j] = Pre[i - 1][j] + Pre[i][j - 1] - Pre[i - 1][j - 1] + Arr[i][j];     int Total = 0;     for (int i = 1; i <= n; i++) {       if (!getSum(i, 1, i, n)) Row[i] = true, Total++;       if (!getSum(1, i, n, i)) Col[i] = true, Total++;     }     for (int x = 1; x + k - 1 <= n; x++) {       int Cur = Total;       for (int i = 1; i < k; i++)         if (!Col[i])           Cur += (getSum(1, i, n, i) - getSum(x, i, x + k - 1, i) == 0);       for (int y = 1; y + k - 1 <= n; y++) {         if (!Col[y + k - 1])           Cur += (getSum(1, y + k - 1, n, y + k - 1) -                       getSum(x, y + k - 1, x + k - 1, y + k - 1) ==                   0);         Add[x][y] += Cur;         if (!Col[y])           Cur -= (getSum(1, y, n, y) - getSum(x, y, x + k - 1, y) == 0);       }     }     for (int x = 1; x + k - 1 <= n; x++) {       int Cur = 0;       for (int i = 1; i < k; i++)         if (!Row[i])           Cur += (getSum(i, 1, i, n) - getSum(i, x, i, x + k - 1) == 0);       for (int y = 1; y + k - 1 <= n; y++) {         if (!Row[y + k - 1])           Cur += (getSum(y + k - 1, 1, y + k - 1, n) -                       getSum(y + k - 1, x, y + k - 1, x + k - 1) ==                   0);         Add[y][x] += Cur;         if (!Row[y])           Cur -= (getSum(y, 1, y, n) - getSum(y, x, y, x + k - 1) == 0);       }     }     int Ans = 0;     for (int i = 1; i <= n; i++)       for (int j = 1; j <= n; j++) Ans = max(Ans, Add[i][j]);     cout << Ans <<   n ;     return 0;   }   