func print_i64[x : I64] : I64
    printf("%ld\n", x)

func gcd[a: I64, b: I64] : I64
    while b != 0
        let tmp: I64 = b
        b = a % b
        a = tmp
    return a

func lcm[a: I64, b: I64] : I64
    return (a * b) / gcd(a, b)

func main[] : I64
    let out: I64 = 1

    let i: I64 = 1
    while i < 21
        out = lcm(out, i)
        i = i + 1
    print_i64(out)