#define  _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
int dp[1005][100];
int len = 1;
void HighAdd( int *dp,int *a,int *b)
{
	for (int i = 0;i < len ; ++i)
	{
		dp[i] += a[i] + b[i];
		if(dp[i]>=10)
		{
			dp[i + 1] += dp[i] / 10;
			dp[i] %= 10;
		}
		if (dp[len + 1]) len++;
	}
}
int main()
{
	int n,start;
	cin >> start;
	cin >> n;
	
	dp[0][0] = 0;
	dp[1][0] = 1;
	for (int i = 2; i <= n-start+1; ++i)
	{
		//dp[i] = dp[i - 1] + dp[i - 2];
		HighAdd(dp[i], dp[i - 1], dp[i - 2]);
	}
	for (int i = len; i >= 0; i--) {
		cout << dp[n][i];
	}
}