text: #include <stdio.h>
  
  int factorial(int n);
  
  int main(void)
  {
    int r;
  
    r = factorial(1);
    printf("%d\n", r);
    r = factorial(5);
    printf("%d\n", r);
    r = factorial(10);
    printf("%d\n", r);
    r = factorial(-1024);
    printf("%d\n", r);
    return (0);
  }
  