func main[] : I64
    let answer: I64 = Math.abs(Math.urandom()) % 100

    while true
        print("Guess a number: ")
        let guess: I64 = IO.read_line() |> String.trim() |> I64.parse()

        if guess == answer
            print("You win!")
            return 0
        else if guess < answer
            print("Too low!")
        else
            print("Too high!")