Computer Programming Contest Preparation

    1 1
    2 IF
    3 ELSE
    4 END_IF
    5 IF
    6 ELSE
    7 END_IF
    8 IF
    9 ELSE
   10 END_IF
   11 ENDPROGRAM
   12 IF
   13 ELSE
   14 END_IF
   15 IF
   16 ELSE
   17 END_IF
   18 IF
   19 ELSE
   20 END_IF
   21 ENDPROGRAM
   22