package main

import . "fmt"
import . "sort"

func main() {
	var t, r int
	Scan(&t, &r)
	ps:=[]int{}
	p := 0
	const P = 1e4
	for ;t>0;t--{
		var n, s int
		Scan(&n)
		for i:=0;i<n;i++ {
			if i+1<n {
				Scan(&s)
			} else {
				Scanln(&s)
			}
			p++
			ps=append(ps,s*P+p)
		}
		if len(ps) > 20 {
			Ints(ps)
			Println(len(ps)/2)
			for i:=len(ps)/2; i>0; i-- {
				Println(ps[0]%P, ps[1]%P)
				ps=ps[2:]
			}
		} else {
			Println(0)
		}
	}
}