Dropping Unnecessary Variables When Building a SAS Data Set from Raw Data

Which is more efficient?

Code 1:

DATA SCORE;
   ARRAY KEY[5] $ 1;
   ARRAY Q[5] $ 1;
   RETAIN KEY1 "A" KEY2 "B" KEY3 "C" KEY4 "D" KEY5 "E";
   INPUT (Q1-Q5)($1.);
   RAW =0;			* Added statement by REJ;
   DO I=1 TO 5;
      RAW+(Q[I]=KEY[I]);
   END;
   PERCENT=100*RAW/5;
DATALINES;
ABCDA
BBCAC
EBCAD
;

Code 2:

DATA SCORE;
   ARRAY KEY[5] $ 1;
   ARRAY Q[5] $ 1;
   RETAIN KEY1 "A" KEY2 "B" KEY3 "C" KEY4 "D" KEY5 "E";
   INPUT (Q1-Q5)($1.);
   RAW = 0;			* Added statement by REJ;
   DO I=1 TO 5;
      RAW+(Q[I]=KEY[I]);
   END;
   PERCENT=100*RAW/5;
   KEEP RAW PERCENT;
   *or DROP KEY1-KEY5 Q1-Q5 I;
DATALINES;
ABCDA
BBCAC
EBCAD
;