def merge(left, right):
    """Merge two lists in ascending order."""
    lst = []
    while left and right:
        if left[0] < right[0]:
            lst.append(left.pop(0))
        else:
            lst.append(right.pop(0))
    if left:
        lst.extend(left)
    if right:
        lst.extend(right)
    return lst