#include <bits/stdc++.h>

#pragma GCC optimize("Ofast")
using namespace std;

void solve(int cs) {
  int n;
  cin >> n;
  map<int,int> v;
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x;
    v[x % 3] += 1;
  }
  int res = 0;
  res += v[0];
  int k = min(v[1], v[2]);
  v[1] -= k, v[2] -= k;
  res += k * 2;
  res += v[1] / 3 * 3;
  res += v[2] / 3 * 3;
  cout << res << "\n";
  
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int tc = 1;
  cin >> tc;
  for (int cs = 1; cs <= tc; cs++) {
    solve(cs);
  }
  return 0;
}