program Bai_9;
var a,b,c : integer;
    p : real;
    s : real;
begin
    writeln('Nhap so a, b, c: ');
    readln(a,b,c);
    p := (a+b+c)/2;
    s := sqrt(p*(p-a)*(p-b)*(p-c));
    writeln('So p la: ',p:0:2);
    writeln('So s la: ',s:0:2);
end.