import typing as tp


def merge(a: tp.Sequence[int], b: tp.Sequence[int]) -> tp.Sequence[int]:
    """
    Merge two sorted lists in one sorted list
    :param a: first sorted list
    :param b: second sorted list
    :return: merged sorted list
    """
    result_list = []
    if len(b) == 0:
        return a
    if len(a) == 0:
        return b
    index_first = 0
    index_second = 0
    while index_first < len(a) and index_second < len(b):
        if a[index_first] < b[index_second]:
            result_list.append(a[index_first])
            index_first += 1
        else:
            result_list.append(b[index_second])
            index_second += 1
    if index_first < len(a):
        result_list.extend(a[index_first:])
    if index_second < len(b):
        result_list.extend(b[index_second:])
    return result_list