import random

def pair(x,y):
    z = 0
    i = 0
    while x > 0 or y > 0:
        z |= (x & 1)<<i
        i += 1
        z |= (y & 1)<<i
        i += 1
        x >>= 1
        y >>= 1
    return z

def unpair(z):
    x = 0
    y = 0
    i = 0
    while z > 0:
        x |= (z & 1) << i
        y |= (z & 2) >> 1 << i
        i += 1
        z >>= 2
    return (x,y)

def pair_many(seq):
    z = pair(seq[0], seq[1])
    for item in seq[2:]:
        z = pair(z, item)
    return z

def unpair_many(z, size):
    result = []
    for _ in range(size-1):
        z, item = unpair(z)
        result.append(item)
    result.append(z)
    result.reverse()
    return result

def pair_many_with_length_data(seq):
    return pair_many(seq + (len(seq),))

def unpair_many_with_length_data(z):
    z, size = unpair(z)
    return unpair_many(z, size)

seq = (4,8,15,16,23,42)
x = pair_many_with_length_data(seq)
print(x)
print(unpair_many_with_length_data(x))