#include
int main(void)
{
int a, b, op;
printf("Enter 0 to add, 1 to subtract: ");
scanf("%d", &op);
if(op == 0) { /* add */
printf("Enter first number: ");
scanf("%d", &a);
printf("Enter second number: ");
scanf("%d", &b);
printf("%d", a+b);
}
else { /* subtract */
printf("Enter first number: ");
scanf("%d", &a);
printf("Enter second number: ");
scanf("%d", &b);
printf("%d", a-b);
}
return 0;
}