import std.algorithm, std.array, std.container, std.range;
import std.string, std.conv;
import std.math, std.bigint, std.bitmanip, std.random;
import std.stdio, std.typecons;

const auto mod = 10 ^^ 9 + 7;

void main()
{
  auto t = readln.chomp.to!int;

  foreach (_; 0..t) {
    auto n = readln.chomp.to!int;
    auto ai = readln.split.map!(to!int).array;

    ai.sort!("a > b");
    auto gi = ai.group.map!("a[1]").map!(to!int).array;
    writeln(calc(gi, 0));
  }
}

int calc(int[] gi, int acc)
{
  if (gi.length < 3) {
    return acc;
  } else {
    gi[0..3] -= 1;
    gi.sort!("a > b");
    return calc(gi.until(0).array, acc + 1);
  }
}