ARC 112

void solve() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    ll B, C;
    cin >> B >> C;

    vector<pair<ll, ll>> ps;
    ps.emplace_back(B - C / 2, B + (C - 2) / 2);
    ps.emplace_back(-B - (C - 1) / 2, -B + (C - 1) / 2);
    sort(all(ps));

    if (ps[0].second >= ps[1].first) {
        ps[0].second = ps[1].second;
        ps.pop_back();
    }

    ll ans = 0;
    for (auto [x, y] : ps) {
        ans += y - x + 1;
    }
    cout << ans << endl;
}