#include <stdio.h>
#define N 3
main()
{
	int a[N][N], i, j, sum=0;

	for (j = 0; j < N; j++)
		for (i = 0; i < N; i++)
			scanf("%d", &a[j][i]);
	for (j = 0; j < N; j++)
		for (i = 0; i < N; i++)
			if (j == i || (i+j == N-1 && i != j) )
				sum += a[j][i];
	printf("Sum is %d\n", sum);
	return 0;
}