#include <iostream>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using u64 = unsigned long long;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208;

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