#include<stdio.h>
#define N 4
void fun(int a[][N],int[])
{int i;
for(i=o;i<N;i++)b[i]=a[i][i]-a[i][N-1-i-]};
}
main( )
{ int x[N][N]={{1,2,3,4},{5,6,7,8},{9,10,11,12},{13,14,15,16}},y[N],i;
fun(X,y);
for(i=0;i<N;i++)printf("%d,",y[i]);printf("\n");
}