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

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