#include <iostream>

using namespace std;
long long v,n,i,j,S,s,r;
int main()
{cin>>n;
for(i=1;i<=n;i++) for(j=1;j<=n;j++){ cin>>v; if(j>i) s=s+v;
if(j<i) S=S+v;}
r=S%s;
while(r){S=s;
s=r;
r=S%s;
}
cout<<s;


}