gistfile1.txt

package main

import (
  "fmt"
  "sync"
)

func main() {
  c1 := make(chan bool)
  c2 := make(chan bool)
  c3 := make(chan bool)
  wg := sync.WaitGroup{}
  wg.Add(1)
  go func (){
    n := 1
	defer wg.Done()
    for {
      fmt.Printf("%d", n)
      fmt.Printf("%d", n+1)
      n += 2
      c1 <- true
      select {
        case <- c2:
        case <- c3: 
          return
      }
    }
  }()
  wg.Add(1)
  go func (){
    m := 'A'
    defer wg.Done()
    for {
      select {
        case <- c1:
      }
      if m >= 'Z' {
        close(c3)
        return
      }
      fmt.Printf("%c", m)
      fmt.Printf("%c", m+1)
      m += 2
      c2 <- true
    }
  }()
  wg.Wait()
  close(c1)
  close(c2)
}