#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define int long long int
template <typename T>
using ordered_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define ld long double
#define nl cout << "\n";
#define getunique(v) {sort(v.begin(), v.end()); v.erase(unique(v.begin(), v.end()), v.end());}
#define forn(a, b) for (int i = a; i < b; i++)
#define __builtin_popcountll __builtin_popcountll
#define __builtin_clzll __builtin_clzll
#define __builtin_ctzll __builtin_ctzll
#define yesno(b) cout << ((b)? "YES" : "NO");
#define pii pair<int, int>
#define mp(a, b) make_pair(a, b)
#define pb push_back
#define all(a) a.begin(), a.end()
#define vi vector<int>
#define hhh cout << "here" << endl;
#define mod1 1000000007
#define mod2 998244353
void solve()
{
    int a, b;
    cin >> a >> b;
    int sum = a + b;
    
    // int minAns = (sum & 1);

    // int mini = min(a, b);
    // a -= mini, b -= mini;

    // int left = a + b;

    // if(left <= mini + mini) {
    //     cout << minAns;
    // }
    // else {
    //     cout << left - mini - mini;
    // }

    int mini = min(a, b);
    a -= mini, b -= mini;

    int curSum = a + b - mini - mini;
    if(curSum <= 0) {
        cout << (sum & 1);
    }
    else {
        cout << curSum;
    }
}
signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);
    int t = 1;
    // cin >> t;
    while (t--)
    {
        solve();
        nl;
    }
    return 0;
}