A.20 B.5 C.10 D.15
A.login 61.27.2.1 B.open 61.27.2.1 C.connect 61.27.2.1 D.telnet 61.27.2.1
A.chown 1.txtsuperman B.chown superman 1.txt C.chname superman1 1.txt D.rm 1.txt