#include <iostream>
#include <stdlib.h>

using namespace std;

#define MAXFIB 10000000

long long fibArray[MAXFIB];

long long fib(int n) {
  if (n <= 1) return 1;
  else if (n == 2) return 1;
  else if (n >= MAXFIB) {
    cout << n  << " is larger than MAXFIB!  Exit.\n";
    exit(0);
  }
  else {
    fibArray[1] = 1;
    fibArray[2] = 1;
    for (int i=3; i <= n; i++) {
      fibArray[i] = fibArray[i-1] + fibArray[i-2];
    }
    return fibArray[n];
  }
}

int main(int argc, char* argv[])
{
  if (argc == 1) cout << "fib(10) = " << fib(10) << "\n";
  else cout << "fib(" << atoi(argv[1]) << ") = " << fib(atoi(argv[1])) << "\n";
 
  return 0;
}