program TriangleSquare;
var
a, b, c, p, S: real;
begin
writeln('Enter the sides of the triangle:');
readln(a, b, c);

p := (a + b + c) / 2;
S := sqrt(p (p - a) (p - b) * (p - c));

writeln('The area of the triangle is: ', S:0:2);
end.