#include <bits/stdc++.h>
using namespace std;

int counts(int m)
{
    if (m == 1 || m == 2)
        return 1;
    return counts(m - 1) + counts(m - 2);
}

int main() {
    int m;
    while(cin>>m)
    {
        cout<<counts(m)<<endl;
    }
    return 0;
}