acpc2016day3C.cpp

signed main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);

    int n;
    cin >> n;
    vi c(3);
    rep(i, n) {
        int a;
        cin >> a;
        c[a%3]++;
    }

    int ans = 1;
    if (c[1] > 0) {
        // 1から使うとき
        int c1 = c[1], c2 = c[2];
        int t = c[0] + 1; c1--;
        int x = min(c1, c2);
        t += 2 * x; c1 -= x; c2 -= x;
        t += max(min(c1, 2), min(c2, 1));
        ans = max(ans, t);
    }
    if (c[2] > 0) {
        // 2から使うとき
        int c1 = c[1], c2 = c[2];
        int t = c[0] + 1; c2--;
        int x = min(c1, c2);
        t += 2 * x; c1 -= x; c2 -= x;
        t += max(min(c2, 2), min(c1, 1));
        ans = max(ans, t);
    }

    cout << ans << endl;

}