50pts,求调，闭关

#include<bits/stdc++.h>
using namespace std;
int s[1005][1005];
int main(){
	int n,m,k,ans=-1;
	cin>>n>>m>>k;
	for(int i=1;i<=n;i++) for(int j=1;j<=m;j++) cin>>s[i][j];
	for(int i=1;i<=n-2;i++){
		for(int j=1;j<=m-2;j++){
			if(max(max(max(max(max(max(max(max(s[i][j],s[i][j+1]),s[i][j+2]),s[i+1][j]),s[i+1][j+1]),s[i+1][j+2]),s[i+2][j]),s[i+2][j+1]),s[i+2][j+2])-min(min(min(min(min(min(min(min(s[i][j],s[i][j+1]),s[i][j+2]),s[i+1][j]),s[i+1][j+1]),s[i+1][j+2]),s[i+2][j]),s[i+2][j+1]),s[i+2][j+2])<k){
				ans=max(ans,s[i][j]+s[i][j+1]+s[i][j+2]+s[i+1][j]+s[i+1][j+1]+s[i+1][j+2]+s[i+2][j]+s[i+2][j+1]+s[i+2][j+2]);
			}
		}
	}
	cout<<ans;
}