package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	reader := bufio.NewReader(os.Stdin)
	writer := bufio.NewWriter(os.Stdout)
	defer writer.Flush()

	var t int
	fmt.Fscan(reader, &t)

	for i := 0; i < t; i++ {
		var n int
		fmt.Fscan(reader, &n)

		c0, c1, c2 := 0, 0, 0
		for j := 0; j < n; j++ {
			var a int
			fmt.Fscan(reader, &a)
			switch a % 3 {
			case 0:
				c0++
			case 1:
				c1++
			case 2:
				c2++
			}
		}

		ans := c0
		if c1 < c2 {
			ans += c1 + (c2-c1)/3
		} else {
			ans += c2 + (c1-c2)/3
		}
		fmt.Fprintln(writer, ans)
	}
}