package main
import(
        "fmt"
        "time"
)

func main(){
        defer timeCost(time.Now())
        fmt.Println("start program")
        time.Sleep(5*time.Second)
        fmt.Println("finish program")
}

func timeCost(start time.Time){
        terminal:=time.Since(start)
        fmt.Println(terminal)
}