S001-AC.cc
350 Bytes
#include <iostream>
#include <string>
using namespace std;
int main()
{
int n,count = 0;
char num;
cin >> n;
if(n < 1)
{
cout << 0 << endl;
return 0;
}
for(int i = 0; i < n; i++)
{
for(int j = 0; j < n; j++)
{
cin >> num;
if(j == n-1 - i || j == i)
{
count += num-48;
}
}
}
cout << count << endl;
return 0;
}