#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define repr(i, a, b) for (int i = (int)(a); i < (int)(b); i++) #define rep(i, n) repr(i, 0, n) #define INF 2e9 #define MOD 1000000007 //#define MOD 998244353 #define LINF (long long)4e18 #define jck 3.141592 #define PI acos(-1.0); const double EPS = 1e-10; using ll = long long; using Pi = pair; using Pl = pair; int main(){ int a,b; cin >> a >> b; if(a > b || b > 2*a){ cout << 0 << endl; } else if(a == b || b == 2*a){ cout << 4 << endl; } else cout << 8 << endl; }