#include <stdio.h>

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

void print_factorial(unsigned int n) {
   printf("Factorial of %llu is %u\n", n, factorial(n));
}

int main(int argc, char** argv) {
   print_factorial(3);
   return 0;
}