#include<iostream>

using namespace std;


int Fibonacci(int n){
	if(n == 1 || n == 0){
		return n;
	}
	return Fibonacci(n -1) + Fibonacci(n - 2);
}


int main(){
	int n;
	while(scanf("%d",&n) != EOF){
		printf("%d\n",Fibonacci(n));
	}
	return 0;
}