package main

import (
	"fmt"
	"os"
	"strconv"
	"sync"
)

func go1(ch chan<- string, wg1 *sync.WaitGroup) {
	defer wg1.Done()
	for i := 1; i < 11; i++ {
		ch <- "go1_" + strconv.Itoa(i)
	}
}

func go2(ch chan<- string, wg1 *sync.WaitGroup) {
	defer wg1.Done()
	for i := 1; i < 11; i++ {
		ch <- "go2_" + strconv.Itoa(i)
	}
}

func Reader(ch <-chan string, wg *sync.WaitGroup) {
	defer wg.Done()
	for {
		if v, ok := <-ch; !ok {
			fmt.Println("Channel closed")
			os.Exit(1)
		} else {
			fmt.Println(v)
		}
	}
}

func main() {
	var wg1 sync.WaitGroup
	var wg sync.WaitGroup
	wg.Add(1)
	wg1.Add(2)
	ch := make(chan string)
	go go1(ch, &wg1)
	go go2(ch, &wg1)
	go Reader(ch, &wg)

	go func() {
		wg1.Wait()
		close(ch)
	}()
	wg.Wait()
}