#include <bits/stdc++.h>

using i64 = long long;

void solve() {
    int n;
    std::cin >> n;
    std::map<int, int> cnt;
    for (int i = 0; i < n; i++) {
        int x;
        std::cin >> x;
        cnt[x]++;
    }
    int s = 0;
    int t = std::min(cnt[1], cnt[-1] / 2);
    s += t;
    cnt[1] -= t;
    cnt[-1] -= t * 2;
    t = cnt[1] / 3;
    s += t;
    cnt[1] -= t * 3;
    t = std::min(cnt[0], (cnt[1] + cnt[-1]) / 2);
    int c = cnt[0] + cnt[1] + cnt[-1];
    c -= 3 * t;
    if (cnt[0] == t) {
        s -= c / 3;
    }
    std::cout << s << "\n";
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    std::cout.tie(nullptr);

    int t;
    std::cin >> t;
    while (t--) {
        solve();
    }
}