#include<bits/stdc++.h>
using namespace std;
int n,a[125][125],b[125][125],ans=-1e9; 
int main(){
    cin>>n;
    for (int i=1;i<=n;i++){
    	for (int j=1;j<=n;j++){
    		cin>>a[i][j];
    		if (j==1) b[i][j]=b[i-1][n]+a[i][j];
    		else b[i][j]=b[i][j-1]+a[i][j];
		}
	} 
	for (int i=1;i<=n;i++){
		for (int j=1;j<=n;j++){
			if (j==1) ans=max(b[i][j]-b[i-1][n],ans);
			else ans=max(b[i][j]-b[i][j-1],ans);
		}
	}
	cout<<ans;
	return 0;
}