#include<bits/stdc++.h>

using namespace std;
using ll = long long;


int main()
{
    int d, e; cin >> d >> e;
    if(d == e || e == 2*d) {
        cout << 4 << endl;
    } else if(e > d && e < 2*d) {
        cout << 8 << endl;
    } else{
        cout << 0 << endl;
    }
}