#include <bits/stdc++.h>
using namespace std;

int main() {
int a, b;
cin >> a >> b;
if (a > b) {
if (3 * b > a) {
cout << (a + b) % 2 << endl;
}
else {
cout << a - 3 * b << endl;
}
}
else {
if (3 * a > b) {
cout << (a + b) % 2 << endl;
}
else {
cout << b - 3 * a << endl;
}
}
}