#include<bits/stdc++.h>
using namespace std;
int m, n, f[10010];
int main()
{
    cin >> m >> n;
    f[1] = 1;
    f[2] = 1;
    f[3] = 2;
    for(int i = m + 3;i <= n;i++)
    {
    	f[i] = f[i - 1] + f[i - 2];
	}
	cout << f[n];
	return 0;
}