What result will the console output in example №15

Determine what will be printed to the console after running the following program.

func main() {
    timeStart := time.Now()
    _, _ = <-worker(), <-worker()
    println(int(time.Since(timeStart).Seconds()))
            
}

func worker() chan int {
    ch := make(chan int)
    go func() {
        time.Sleep(3 * time.Second)
        ch <- 1        
    }()
    return ch        
            
}