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

int main() {
int64_t a, b;
cin >> a >> b;
int c = 0;
if (a > b) {
if ((3 * b) >= a) {
c = (a + b) - (a + b) / 2 * 2;
}
else {
c = a - 3 * b;
}
}
else if (a < b) {
if ((3 * a) >= b) {
c = (a + b) - (a + b) / 2 * 2;
}
else {
c = b - 3 * a;
}
}
else {
c = 0;
}
cout << c << endl;
}