dic = {
    'reset': 'reset what',
    'reset board': 'board fault',
    'board add' : 'where to add',
    'board delete' : 'no board at all',
    'reboot backplane': 'impossible',
    'backplane abort' : 'install first'
}

key = list(dic.keys())
value = list(dic.values())	
	
while True:
    try:
        pass
        line = input()
        cmd = line.split()
        if len(cmd) != 1 and len(cmd) != 2:
            print('unknown command')
            continue

        if len(cmd) == 1:
            if 'reset'.startswith(cmd[0]):
                print(dic[key[0]])
                continue
            else:
                print('unknown command')
                continue
        tmp = []
        for k in key[1:]:
            kk = k.split()
            if kk[0].startswith(cmd[0]) and kk[1].startswith(cmd[1]):
                tmp.append(k)
        if len(tmp) != 1: # 可以把满足条件的都记录下来,然后再判断是否唯一
            print('unknown command')
            continue
        else:
            print(dic[tmp[0]])
            continue

            
    except EOFError:
        break