def time_warp(ts):
    """
    >>> time_warp('1 2 3 4 5 5 2 3 3'.split(' '))
    ['1', '2', '3', '4', '5', '2', '3']
    """
    
    ts = ts.split(' ')
    result = []
    most_recent_elem = None
    for e in ts:
        if e != most_recent_elem:
            result.append(e)
            most_recent_elem = e

    return result