var a,b:array[0..50000] of integer;
    c,t:array[0..50000] of longint;
	tot:array[1..50000] of real;
	n,l,u,i,st,dr:longint;
	min,max,rez:real;

begin
assign(input,'secv3.in'); reset(input);
assign(output,'secv3.out');rewrite(output);
readln(n,l,u);
for i:=1 to n do read(a[i]);
readln;
for i:=1 to n do read(b[i]);

for i:=1 to n do
begin
	c[i]:=c[i-1]+a[i];
	t[i]:=t[i-1]+b[i];
	tot[i]:=c[i]/t[i];
end;

for i:=L to n do if tot[i]>max then
begin
	max:=tot[i];
	DR:=i;
end;

max:=0;
for i:=dr-L downto dr-U do
begin
	if (c[dr]-c[i])/(t[dr]-t[i])>max then
	begin
		max:=(c[dr]-c[i])/(t[dr]-t[i]);
		st:=i;
	end;
end;

rez := (c[dr]-c[st])/(t[dr]-t[st]);

writeln(rez:0:2);
close(input); close(output);
end.