A = ['reset', 'board', 'board','reboot', 'backplane']
B =['board', 'add', 'delete', 'backplane', 'abort']
C = ['board fault', 'where to add', 'no board at all','impossible','install first']
def check(s):
    if len(s) == 1:
        if 'reset'.startswith(s[0]):
            return 'reset what'
        else:
            return 'unknown command'
    elif len(s) == 2:
        flag = 0
        temp = []
        for i, x in enumerate(A):
            if x.startswith(s[0]) and B[i].startswith(s[1]):
                flag += 1
                temp.append(C[i])
        if flag == 0 or flag == 2:
            return 'unknown command'
        else: 
            return temp[0]
    else:
        return 'unknown command'


while True:
    try:
        s = input().split()
        print(check(s))
    except:
        break