#include <stdio.h>
#include <stdlib.h>
#define N 3
#define M 3
int main()
{
int matrix[M][N]={ {1, 2, 3},
{4, 5, 6},
{6, 7, 8} };
int i, sum_2 = 0, sum = 0, sum_3;
for(i = 0; i < M; i++)
{
sum += matrix[i][i];
if(i != (M - 1 - i))
{
sum_2 += matrix[i][M - 1 - i];
}
sum_3 = sum + sum_2;
}
printf("%d", sum_3);
return 0;
}
