前缀和，子矩阵的和

#include <iostream>

using namespace std;

const int N = 610;

int n, l, r, t ;
int matrix[N][N];
int s[N][N];

int getSum(int x1, int y1, int x2, int y2){
    return s[x2][y2] - s[x1-1][y2] - s[x2][y1-1] + s[x1-1][y1-1];
}

int main() {
    cin >> n >> l >> r >> t;
    int ans = 0;
    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            cin >> matrix[i][j];
        }
    }

    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            s[i][j] = s[i-1][j] + s[i][j-1] - s[i-1][j-1] + matrix[i][j];
        }
    }

    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            int x1 = max(0, i-r); 
            int y1 = max(0, j-r); 
            int x2 = min(i+r, n-1); 
            int y2 = min(j+r, n-1);
            int count = (x2 - x1 + 1) * (y2 - y1 + 1); 
            int cur = getSum(x1, y1, x2, y2);
            //printf("cur = %d\n", cur);
            if(cur <= t * count){
                ans++;
            }
        }
    }
    printf("%d\n", ans);

    return 0;
}