def subsequence(niddle, haystack):
    """
    Check if niddle is subsequence of haystack
    """
    niddle, haystack = niddle.lower(), haystack.lower()
    if not niddle:
        return True
    offset = 0
    for char in niddle:
        offset = haystack.find(char, offset) + 1
        if offset <= 0:
            return False
    return True