import java.math.BigInteger;  
import java.util.Scanner;  
  
public class Main{
  
    public static void main(String[] args) {  
        Scanner in = new Scanner(System.in);  
        BigInteger[] ans = new BigInteger[250];  
        ans[1] = new BigInteger("1");  
        ans[2] = new BigInteger("2");  
          
        int i;  
        for(i = 3 ; i <= 200 ; ++i){  
            ans[i] = ans[i-1].add(ans[i-2]);  
        }  
          
        while(in.hasNext()){  
            int n = in.nextInt();  
            if(n==0) 
                System.out.println();
            else
                System.out.println(ans[n]);  
        }  
    }  
      
}