uses crt;
var
a,b:integer;
function lg(x:real):real;
var
c:real;
begin
c:=0.4343*ln(x);
lg:=c;
end;
function oper(a,b:real):real;
var
y:real;
begin
y:=(lg(a)-lg(b))/2*lg(a+b);
writeln(y:2:5);
end;
begin
clrscr;
readln(a);
readln(b);
oper(a,b);
readkey;
end.