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

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