magickvdrt

#include <iostream>
using namespace std;
int a[25][25];
int main()
{
    int sum=0,n,summ=0;
    cin>>n;
    for(int i=0;i<n;++i)
        for(int j=0;j<n;++j)
            cin>>a[i][j];
    for(int i=0;i<n;++i)
        sum+=a[i][i];
    for(int i=0;i<n;++i)
        summ+=a[i][n-i-1];
    if(summ!=sum){cout<<summ<<"No";return 0;};
    for(int i=0;i<n;++i)
    {
        int summ=0;
        for(int j=0;j<n;++j)
            summ+=a[i][j];
        if(summ!=sum){cout<<"No";return 0;};
    }
      for(int i=0;i<n;++i)
    {
        int summ=0;
        for(int j=0;j<n;++j)
            summ+=a[j][i];
        if(summ!=sum){cout<<"No";return 0;};
    }
    cout<<"Yes";
    return 0;
}