var f,g:text;
a,c,t,p:array[0..30000] of longint;
ok:boolean;
n,l,u,j,i,k:longint;max:extended;
begin
assign(f,'secv3.in');
assign(g,'secv3.out');
reset(F);
rewrite(G);
readln(f,n,u,l);
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 i+l-1 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.