package main

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

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

	var n int
	if _, err := fmt.Fscan(in, &n); err != nil {
		return
	}

	f := make([]int, 8)
	for i := 0; i < n; i++ {
		var x int
		fmt.Fscan(in, &x)
		if x >= 0 && x < 8 {
			f[x]++
		}
	}

	if f[5] > 0 || f[7] > 0 {
		fmt.Fprintln(out, -1)
		return
	}

	x := f[4]
	z := f[3]
	y := f[2] - x

	if y < 0 || f[6] != y+z || f[1] != x+y+z {
		fmt.Fprintln(out, -1)
		return
	}

	for i := 0; i < x; i++ {
		fmt.Fprintln(out, "1 2 4")
	}
	for i := 0; i < y; i++ {
		fmt.Fprintln(out, "1 2 6")
	}
	for i := 0; i < z; i++ {
		fmt.Fprintln(out, "1 3 6")
	}
}