#include<iostream>
 
using namespace std;
 
int main(){
	int n, numeros[100][100], suma=0, suma2=0, conteo=0;
 
	cin >> n;
 
	for(int i=0; i<n; i++){
		for(int j=0; j<n; j++){
			cin >> numeros[i][j];
		}
	}
 
 
	for(int i=0; i<n; i++){                     
		for(int j=0; j<n; j++){
			if(i==j){
				suma += numeros[i][j];
			}
		}
	}
 
	for(int i=0; i<n; i++){                     
		for(int j=0; j<n; j++){
			if(j+i == n-1){
				suma2 += numeros[i][j];
			}
		}
	}
 
	for(int i=suma; i<suma2; i++){
		conteo++;
	}
 
	cout<<conteo<<endl;
 
	return 0;
}

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NQoxMSAyIDQgNCA1CjQgNSA2IDMgMwoxMCA4IDEyIDIyIDEyCjIgMTIgMTIgMjMgMjMKMzQgMTIgMTIgMzIgMTI=

5
11 2 4 4 5
4 5 6 3 3
10 8 12 22 12
2 12 12 23 23
34 12 12 32 12