var f:text;
    suma,timp,i,n,lmin,lmax,pi,nr:integer;
    r,rmax:real;
    s,t:array[1..10000] of integer;
BEGIN
assign(f,'secv3.in');
reset(f);
readln(f,n,lmin,lmax);
for i:=1 to n do read(f,s[i]);
for i:=1 to n do read(f,t[i]);
pi:=0;
r:=0;
rmax:=0;
close(f);
while pi<=n-lmin do
begin
       inc(pi);
       suma:=s[pi];
       timp:=t[pi];
       i:=pi;
       nr:=1;
       while (nr>=lmin) and (nr<lmax) do
        begin

                 if r <  ((suma+s[i])/(timp+t[i])) then
                     begin
                            suma:=suma+s[i];
                            timp:=timp+t[i];
                            r:=suma/timp;
                     end
                     else
                 if r < (s[i]/t[i]) then
                        begin
                                 pi:=i;
                                 suma:=s[i];
                                 timp:=t[i];
                                 nr:=1;
                                 r:=suma/timp;
                        end
                    else
                  if (suma/timp) > (s[i]/t[i])  then begin
                                                           r:=suma/timp;
                                                           break;
                                                     end;
             inc(i);
             inc(nr);
           end;

           if r>rmax then rmax:=r;
end;
assign(f,'secv3.out');
rewrite(f);
writeln(f,rmax:5:2);
close(f);
end.