package main

import (
	"fmt"
	"time"
)

func main() {
	start := time.Now()
	defer func() {
		end := time.Now()
		fmt.Println(end.Sub(start))
	}()

	var (
		n   = 3
		x   = 4
		iar = []int{1, 2, 3}
	)

	print("[")
	for i, v := range iar {
		for _, vv := range iar {
			this := v + vv
			if x == this {
				fmt.Printf("[%d, %d]", v, vv)

			}
		}
		if i < n-1 {
			print(",")
		}
	}
	println("]")

}