def solution(record):
    table = {}
    room = []
    answer = []
    for i in record :
        tmp = i.split(' ')
        if len(tmp) == 3 :
            action, ID, name = tmp
            table[ID] = name
        else :
            action, ID = tmp
        room.append([ID, action])
        
    for ID, action in room :
        if action == 'Change' :
            continue
        if action == 'Enter' :
            answer.append('{}님이 들어왔습니다.'.format(table[ID]))
        else :
            answer.append('{}님이 나갔습니다.'.format(table[ID]))
    return answer