data ctr1;
 input center$ treat$ s n; f=n-s;
 datalines;
 a 1 11 36
 a 2 10 37 
 b 1 16 20
 b 2 22 32 
 c 1 14 19
 c 2 7  19 
 d 1 2  16
 d 2 1  17 
 e 1 6  17
 e 2 0  12 
 f 1 1  11
 f 2 0  10 
 g 1 1  5
 g 2 1  9 
 h 1 4  6
 h 2 6  7 
;
data ctr2; set ctr1;
 do i=1 to n; if i<=s then y=1; else y=0; output; end;