#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll, ll> P;
typedef vector<ll> VI;
typedef vector<VI> VVI;
const ll MOD = 1000000007;
const ll INF = 2147483647;
const ll LINF = 9223372036854775807;
#define REP(i, n) for (int i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()

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