#include <bits/stdc++.h>
#include <atcoder/all>
 
#define elif else if
#define ll long long
#define vll vector<long long>
#define vec vector
#define embk emplace_back
#define rep(i, n) for (int i = 0; i < n; i++)
#define rep3(i, n, k) for (int i = k; i < n; i++)
#define all(a) a.begin(), a.end()
 
using namespace std;
using namespace atcoder;
const ll INF = 1LL << 60;
const ll mod = 998244353;

int main() {
  ll a, b; cin >> a >> b;
  if (a == b) {
    if (a % 2 == 0) cout << 0 << endl;
    else cout << 2 << endl;
  }
  else cout << abs((a+b) - min(a,b) * 4) << endl;
  
}