#include <iostream>

using namespace std;
long fib_table[101] = {};

long fib(int n){
	if(n == 1){
		return 1;
	}
	if(n == 2){
		return 2;
	}

	if(fib_table[n] == 0){
		fib_table[n] = fib(n-1) + fib(n-2);
	}

	return fib_table[n];

}

int main(){	
	long n; 
	while(cin >> n){
		if (n == 0){
			break;
		}
		cout << fib(n) << endl;
	}

	return 0;	
}