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

public class Main {
    public static void main(String[] args) {
        BigInteger[] a = new BigInteger[220];
        a[0] = a[1] = BigInteger.ONE;
        for(int i = 2; i <= 200; ++i) {
            a[i] = a[i-1].add(a[i-2]);
        }
        Scanner in = new Scanner(System.in);
        while(in.hasNextInt()) {
            System.out.println(a[in.nextInt()]);
        }
    }
}