#print
In this directory there is a file "pres" in which
either the 5th line or the 6th line does not
belong.  Edit the file, print the dubious lines,
delete the bad one, and then rewrite the file.
Then type "ready".
#create Ref
george washington
john adams
thomas jefferson
james madison
james monroe
john quincy adams
andrew jackson
martin van buren
william henry harrison
john tyler
#create pres
george washington
john adams
thomas jefferson
james madison
james monroe
 this is wrong Qwertyuiop
john quincy adams
andrew jackson
martin van buren
william henry harrison
john tyler
#user
#cmp pres Ref
#log
#next
19.2d 5