import java.util.*;
import java.math.*;
public class Main {
    public static void main(String[] args) {
        Scanner in=new Scanner(System.in);
        BigInteger[] a=new BigInteger[210];
        a[0]=BigInteger.ONE;
        a[1]=BigInteger.ONE;
        for(int i=2;i<=200;i++){
            a[i]=a[i-1].add(a[i-2]);
        }
        while(in.hasNextInt()){
            int n=in.nextInt();
            System.out.println(a[n]);
        }
        in.close();
    }
}