import java.math.*;
import java.util.*;

public class Main {
    public static void main(String[] args)
    {
        Scanner cin = new Scanner(System.in);
        int n;
        BigInteger ans[] = new BigInteger[201];
        ans[1] = BigInteger.ONE;
        ans[2] = BigInteger.valueOf(2);
        for(int i=3;i<201;i++) ans[i] = ans[i-1].add(ans[i-2]);
        while(cin.hasNext() )
        {
            n = cin.nextInt();
            System.out.println(ans[n]);
        }
    }
}