我这代码第一次WA都下载了数据，跟数据输出一样，他还判我错

#include<bits/stdc++.h>
using namespace std;

int n,m,c;
const int N = 1e3 + 10;
int a[N][N],s[N][N];
int ans = INT_MIN,x,y;

int main(){
	cin >> n >> m >> c;
	for(int i = 1;i <= n;i++){
		for(int j = 1;j <= n;j++){
			cin >> a[i][j];
		}
	}
	for(int i = 1;i <= n;i++){
		for(int j = 1;j <= m;j++){
			s[i][j] = s[i - 1][j] + s[i][j - 1] - s[i - 1][j - 1] + a[i][j];
		}
	}
	for(int i = 0;i <= n;i++){
		int k = i + c - 1;
		if(k > n){
			break;
		}
		for(int j = 1;j <= m;j++){
			int h = j + c - 1;
			if(h > m){
				break;
			}
			int S = s[k][h] + s[i - 1][j - 1] - s[i - 1][h] - s[k][j - 1];
			if(S > ans){
				ans = S;
				x = i;
				y = j; 
			}
		}
	}	
	cout << x << " " << y << endl; 
	return 0;
} 

我是蒻蒟 求大佬帮忙看看蒻蒟写的破代码~