import java.math.BigInteger;  
import java.util.Scanner;  
  
public class Main {
  
    public static void main(String[] args) {  
        Scanner scanner = new Scanner(System.in);  
          
        BigInteger[] fibs = new BigInteger[205];  
          
        fibs[1] = new BigInteger("1");  
        fibs[2] = new BigInteger("2");  
          
        int i;  
        for(i = 3 ; i < 205 ; ++i){  
            fibs[i] = fibs[i-1].add(fibs[i-2]);  
        }  
          
        while(scanner.hasNext()){  
            int n = scanner.nextInt();  
              if(n==0)
                  System.out.println(); 
              else
                  System.out.println(fibs[n]);  
        }  
    }  
      
}