#include <iostream>
#include <algorithm>
#include <string.h>

using namespace std;
int  dp[1000000];
int f(int x)
{
    if(dp[x] != 0)
    {
        return dp[x];
    }
    int res;
    if(x == 0)
        return 1;
    if(x < 0)
        return 0;
    if(x == 1)
        res = 1;
    else
        res = f(x-1)+f(x-2);
    return dp[x] = res;
}
int main()
{
   int x;
   cin>>x;
   while (x != 0)
   {
       cout<<f(x)<<endl;
       cin>>x;
   }
    return 0;
}