#include <iostream>

using namespace std;


unsigned int fibo1(unsigned int n)
{
  unsigned int current, back, twoback;

  twoback=1;
  current = back = 1;

  for (int i=2; i<=n; i++) {
    current = back+twoback;
    twoback=back;
    back = current;
  }
 
  return current;

}


int main() {

  unsigned int input = 1;

  while (input != 0) {
    cout << "Enter the number: ";
    cin >> input;
    cout << "The result is " << fibo1(input) << endl;;
  }

  return 0;
}