def pretty_print(n):
    """Pretty print function for very big integers"""
    if not isinstance(n, int):
        return n
    ret = []
    n = str(n)
    for i in range(len(n) - 1, -1, -1):
        ret.append(n[i])
        if (len(n) - i) % 3 == 0:
            ret.append(',')
    ret.reverse()
    return ''.join(ret[1:]) if ret[0] == ',' else ''.join(ret)
