Ответ:

program n1;

var a, b, c:integer;

begin

readln(a, b, c);

writeln((a+b+c)/2);

writeln(a*b*c/2);

writeln(a-b);

writeln(a-c);

end.

program n2;

var a, b:integer;

begin

readln(a);

b:=6*sqr(a);

writeln(b);

end.

program n3;

var a, b:integer;

begin

readln(a, b);

if 1/a<1/b then

writeln('Теннисистов')

else writeln('Пловцов');

end.