var
x,y,z,U:real;
function Max(a,b:real):real;
begin
if a > b then Max:=a else Max:=b;
end;
begin
write('x=');
readln(x);
write('y=');
readln(y);
write('z=');
readln(z);
U:=(max(x,y)+max(x+y,x*z))/sqr(max(0.5,x+z));
writeln;
writeln('U=',u:15:3);
readln;
end.