#include
int main()
{
int i,j,sum;
int angs[4][4];
printf("请输入矩阵:\n");
sum = 0;
for(i = 0; i < 4; i++)
for(j = 0; j < 4; j++)
{
scanf("%d",&angs[i][j]);
if(i == j || i+j == 3)
sum += angs[i][j];
}
printf("%d\n",sum);
return 0;
}