# 抄了评论区比较稳的代码记一下
import sys

for line in sys.stdin:
    s = line.split()
    if s[0] in "reset" and len(s)==1:
        print("reset what")
    elif len(s)==2:
        if s[0] in 're' and s[1]=='b':
            print("unknown command")
        elif s[0]=='b' and s[1]=='a':
            print("unknown command")
        elif s[0] in "reset" and s[1] in "board":
            print("board fault")
        elif s[0] in "board" and s[1] in "add":
            print("where to add")
        elif s[0] in "board" and s[1] in "delete":
            print("no board at all")
        elif s[0] in "reboot" and s[1] in "backplane":
            print("impossible")
        elif s[0] in "backplane" and s[1] in "abort":
            print("install first")
        else:
            print("unknown command")
    else:
        print("unknown command")