#include<bits/stdc++.h>
#define ll long long
#define endl "\n"
using namespace std;

int main() {
    ios_base::sync_with_stdio(0);cin.tie(0);
    int t,a,b,x;   cin >> t; 
    while(t--){
        cin >> a;
        map<int,int>m;
        while(a--){
            cin >> x;
            m[x]++;
        }
        if(m[0])    cout << 0 << endl;
        else    cout << (m[1]/3) - ((m[-1]+(m[1]%3))/3) << endl;
    }
  return 0;
}