using namespace std;
#include <iostream>


long long f (int n) 
{
  long long res;  
  if (n==0||n==1) 
    res = 1;
  else
    res = f(n-1)+f(n-2);
  return res;
}

int main() 
{
  int n;
  cout << "n? ";
  cin >> n;
  cout << "f(" << n << ") = " << f(n) << endl;
return 0;
}