import java.math.*;
import java.io.*;
import java.util.*;
 
public class Main {
 
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        BigInteger[] dp = new BigInteger[205];
        dp[1] = BigInteger.ONE;
        dp[2] = BigInteger.ONE.add(BigInteger.ONE);
        for (int i=3; i<=200; ++i) {
            dp[i] = dp[i-1].add(dp[i-2]);
        }
         
        Scanner cin = new Scanner (System.in);
        int n;
        while (cin.hasNext ()) {
            n = cin.nextInt ();
            System.out.println (dp[n]);
        }
    }
     
    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;
 
        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }
 
        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }
 
        public int nextInt() {
            return Integer.parseInt(next());
        }
    }
}