program pascal;
var f,g:text;
    i,j,n,k,u,aux1,aux2:longint;
    max:real;
    cost,timp,sumac,sumat:array[0..30000] of longint;
begin
assign(f,'secv3.in'); reset(f);
assign(g,'secv3.out'); rewrite(g);
readln(f,n,k,u);
for i:=1 to n do read(f,cost[i]);
readln(f);
for i:=1 to n do read(f,timp[i]);

for i:=1 to n do
  begin
    sumac[i]:=sumac[i-1]+cost[i];
    sumat[i]:=sumat[i-1]+timp[i];
  end;

max:=-2000000000;
for i:=1 to n-k+1 do
  begin
    aux1:=sumac[i+k-1]-sumac[i-1];
    aux2:=sumat[i+k-1]-sumat[i-1];
    if aux1/aux2>max then max:=aux1/aux2;

    for j:=i+k to i+u-1 do
    if j<=n then
     begin
        aux1:=aux1+cost[j];
        aux2:=aux2+timp[j];
        if aux1/aux2>max then  max:=aux1/aux2;
     end else break;
   end;


write(g,max:0:2);
close(f);
close(g);
end.