data ok;
  input gender $ weight @@;
   if weight>300 then delete;
  cards;
m 157  f 123  m 122  f 911
f  97  f  23  m 212  f
121  f  97  f  23
proc print;

data males;
  input gender $ weight @@;
   if gender='f' then delete;
  cards;
m 157  f 123  m 122  f 911
f  97  f  23  m 212  f 121
.  97  f  23
proc print;