#include<bits/stdc++.h>
using namespace std;
int main(){
	int n , f[1000] , m;
	cin >> m >> n;
	f[m + 1] = 1; f[m + 2] = 2;
	for(int i = m + 3 ; i <= n ; i++){
		f[i] = f[i - 1] + f[i - 2];
	}
	cout << f[n];
	return 0;
}