package main
import (
    "os"
    "fmt"
    "bufio"
    "strconv"
)

func doubler(v int, ch chan int) {
	ch <- v * 2
}

func main() {
	var num string
	file, _ := os.Open("IN.A")
	out, _ := os.Create("OUT")
	defer out.Close()
	s := bufio.NewScanner(file)
	c := make(chan int)
	for s.Scan() {
		num = s.Text()
		numi, _ := strconv.ParseInt(num, 0, 0)
		go doubler(int(numi), c)
		out.WriteString(fmt.Sprintf("%d\n",int(<-c)))
	}
}