program secventa3;
var f,g:text;
    a,b:array[0..30000]of longint;
    max:real;
    cs,cs2,n,i,l,u,s,s2,j,k:longint;
begin
assign(f,'secv3.in');
assign(g,'secv3.out');
reset(f);
rewrite(g);
read(f,n,l,u);
for i:=1 to n do read(f,a[i]);
for i:=1 to n do read(f,b[i]);
s:=0;
s2:=0;
for i:=1 to l-1 do
  begin
    s:=s+a[i];
    s2:=s2+b[i];
  end;
a[0]:=0;
b[0]:=0;
if (s<>0)and(s2<>0)then
if (s/s2>max)then max:=s/s2;
cs:=s;
cs2:=s2;
for k:=l to u do
  begin
    s:=cs;
    s2:=cs2;
    s:=s+a[k];
    s2:=s2+b[k];
    cs:=s;
    cs2:=s2;
    if (s/s2>max)then max:=s/s2;
    i:=k;
    while(i<n) do
      begin
        i:=i+1;
        s:=s-a[i-k]+a[i];
        s2:=s2-b[i-k]+b[i];
        if (s/s2>max)then max:=s/s2;
      end;
  end;
write(g,max:6:2);
close(f);
close(g);
end.