func leastCommonMultiple(_ n: UInt64) -> UInt64 {
    var res: UInt64 = 1
    let primes: [UInt64] = [2,3,5,7,11,13,17,19,23,29,31,37,41,43]
    var mcm = Array(1...n)
    var pi = 0
    var mc = 1
    while mc <= n {
        var dc = 1
        mc = 1
        for i in 0..<mcm.count {
            if mcm[i] % primes[pi] == 0 {
                mcm[i] /= primes[pi]
            } else {
                dc += 1
            }
            if mcm[i] == 1 {
                mc += 1
            }
        }
        if dc > n {
            pi += 1
        } else {
            res *= primes[pi]
        }
    }
    return res
}