var v,x:array[1..15000] of integer;
    n,i,c,q,p,k,u,j,l,d:0..50000;
    f,g:text;
    r,max:real;
    s,s2:longint;
begin
assign(f,'secv3.in');
assign(g,'secv3.out');
reset(f);
rewrite(g);
readln(f,n,d,u);
s:=0;
max:=-maxlongint;
for i:=1 to n do read(f,v[i]);
readln(f);
max:=0;
for i:=1 to n do read(f,x[i]);
for i:=1 to n do begin j:=i;
                       l:=0;
                       s:=0;  s2:=0;
                       repeat
                       s:=s+v[j]; s2:=s2+x[j];
                       l:=l+1;
                       r:=s/s2;
                       if (l>=d) and(l<=u) and (r>=max) then max:=r;
                       j:=j+1;
                                               until j>n;
                                               end;
writeln(g,max:3:2);
close(f);
close(g);
end.