#include <stdio.h>
#include <stdlib.h>

int a[128];

int fib(int n);


int main(int argc, char* argv[])
{
  int n;
  int m;

  if (argc < 2 ) {
    n = 5;
  } else {
    if ( sscanf(argv[1], "%d", &n) != 1 ) {
      n = 5;
    }
  }
  m = fib(n);
  printf("fib(%d) = %d\n", n, m);

  return 0;
}

int fib(int n)
{
  if ( n == 0 || n == 1 ) {
    return 1;
  } else {
    int tmp = fib(n - 1) + fib(n - 2);
    return tmp;
  }
}