PROC PLAN SEED=210002 ;
FACTORS    block =60 length =6 ;
OUTPUT OUT =fff ;
DATA ggg ;
SET fff ;
number = _n_ ;
IF length <=2 THEN group='A' ;
ELSE IF length <=4 THEN group='B' ;
ELSE group='C' ;
PROC PRINT NOOBS ;
VAR number group ;
RUN;