#include <iostream>
using namespace std;
int main() {
    long long i, j, iDel; long long biggestV = 9999999, biggestDel = 9999999;
    cin >> i >> j;
    if (i == 1) {
        cout << 1;
        return 0;
    }
    else if (i == j) {
        cout << i;
        return 0;
    }
    else if (i + 1 == j) {
        cout << (j % 2 != 0 ? j : i);
        return 0;
    }
    for (long long iV = j % 2 != 0 ? j : j-1; iV >= i; iV -= 2) {
        for (iDel = j / 3 + 1; iDel >= 1; iDel--) {
            if (iV%iDel == 0) {
                if (iDel < biggestDel) {
                    biggestDel = iDel;
                    biggestV = iV;
                }
                break;
            }
        }
        if (iDel == 1) {
            cout << iV;
            return 0;
        }
    }
    cout << biggestV;
}