题解 | #配置文件恢复#

while True:
    try:  #对小白来说很好理解，没有那么多技巧，但是很实用

        a=input().split()
        b=len(a)
        l1=['reset']
        l2=['reset ','board']
        l3=['board','add']
        l4=['board','delete']
        l5=['reboot','backplane']
        l6=['backplane','abort']
        if b==1:

            if a[0]==l1[0][0:(len(a[0]))]:
                print('reset what')   
            else:
                print('unknown command')
        else:


            x,y=a[0],a[1]
            m,n=len(a[0]),len(a[1])
            if a[0]==l2[0][0:m] and a[1]==l2[1][0:n] and not(a[0]==l5[0][0:m] and a[1]==l5[1][0:n]):
                print('board fault')
                
            elif a[0]==l3[0][0:m] and a[1]==l3[1][0:n] and not(a[0]==l6[0][0:m] and a[1]==l6[1][0:n]):
                print('where to add')

            elif a[0]==l4[0][0:m] and a[1]==l4[1][0:n]:
                print('no board at all')
                
            elif a[0]==l5[0][0:m] and a[1]==l5[1][0:n]and not(a[0]==l2[0][0:m] and a[1]==l2[1][0:n]):
                print('impossible')
            elif a[0]==l6[0][0:m] and a[1]==l6[1][0:n] and not(a[0]==l3[0][0:m] and a[1]==l3[1][0:n]):
                print('install first')
            else:
                print('unknown command')                

    except:
        break