data a;
name=80; math=75;chinese=79;english=98;output;
name=100; math=98;chinese=65;english=98;output;
name=98; math=96;chinese=93;english=86;output;
run;
data b;
sex='f';output;
sex='m';output;
sex='f';output;
run;
data c;
retain name sex math chinese english;
merge a
b;
run;