#include <iostream>

using namespace std;

int a[101][101], sp,ss,n;

void citire ()
{
    cin>>n;
    for (int i=1;i<=n;i++)
        for (int j=1;j<=n;j++)
        {
            cin>>a[i][j];
//            if (i==j)
//                sumdiag+=a[i][j];
//            if (i+j==n+1)
//                sumgiag2+=a[i][j];
        }
    for (int i=1;i<=n;i++)
    {
        sp+=a[i][i];
        ss+=a[i][n-i+1];
    }
    if (sp>ss)
        cout<<sp-ss;
    else cout<<ss-sp;

}

int main()
{
   citire();
    return 0;
}