var f,g:text;
    a,c,t,p:array[0..30000] of real;
    ok:boolean;
    n,l,u,j,i,k:longint;max:real;

function min(x,y:longint):longint;
   var k:longint;
   begin
     if x>y then k:=y
            else k:=x;
     min:=k;
   end;

begin
  assign(f,'secv3.in');
  assign(g,'secv3.out');
  reset(F);
  rewrite(G);
  readln(f,n,u,l);
  max:=0;
  for j:=1 to n do
    read(f,c[j]);
  for i:=1 to n do
    p[i]:=p[i-1]+c[i];
  for i:=1 to n do
    read(f,a[i]);
  for i:=1 to n do
    t[i]:=t[i-1]+a[i];
  for i:=1 to n-u+1 do
    for j:=i+u-1 to min(min(n,i+l-1),i+u+1000) do
      if (p[j]-p[i-1])>max*(t[j]-t[i-1]) then max:=(p[j]-p[i-1])/(t[j]-t[i-1]);
  writeln(g,max:0:2);
  close(F);
  close(G);
end.