#include <cmath>
#include <vector>
#include <iostream>
#include <algorithm>

using namespace std;

vector<int> Eratosthenes(int n){
	bool dp[n];
	for(int i = 0; i < n; i++) dp[i] = false;
	dp[0] = dp[1] = true;
	vector<int> prime;
	for(int i = 2; i < n; i++){
		if(dp[i]) continue;
		prime.push_back(i);
		for(int j = i * i; j < n; j += i){
			dp[j] = true;
		}
	}
	return prime;
}

int main(){
	long long l, h;
	cin >> l >> h;
	vector<int> prime = Eratosthenes(10000);

	long long ans;
	long long so = -1;
	for(long long i = l; i <= h; i++){
		for(long long j = 0; j < prime.size(); j++){
			if(i % prime[j] == 0){
				if(i == prime[j]) break;
				if(so <= j){
					ans = i;
					so = j;
				}
				break;
			}
		}
	}

	cout << ans << endl;

	return 0;
}