#include <stdio.h>

unsigned long int factorial(unsigned int n){
  if (n == 0)
    return 1;
  else 
    return n * factorial(n - 1);
}

int main(void) {
  unsigned int k;

  /* Upper limits of k:  12  (if long is 4 bytes) */
  /* Upper limits of k:  20  (if long is 8 bytes) */

  for (k = 1; k <= 12; k++)                     
    printf("%-20u %20lu\n", k, factorial(k));
  
  return 0;
}