var t:array[1..3,1..30000] of real;
    i,n,l,u,m,ultim:integer;
     s:real;
Procedure Buble;
var    aux:real;
    i,j:integer;
Begin
for i:=1 to n do
for j:=i to n do
if t[3,i]<t[3,j] then
   begin
        aux:=t[3,i];
        t[3,i]:=t[3,j];
        t[3,j]:=aux;
   end;
End;

BEGIN
assign(input,'secv3.in');
reset(input);
readln(N,l,u);
for i:=1 to n do
read(t[1,i]);
readln;
for i:=1 to n do
read(t[2,i]);
close(input);
for i:=1 to n do
t[3,i]:=t[1,i]/t[2,i];
Buble;
writeln;
s:=0;
for i:=1 to l do
s:=s+t[3,i];
ultim:=l;
while (ultim<=u) and (t[3,l]=t[3,ultim+1])
      do
        begin
             ultim:=ultim+1;
             s:=s+t[3,ultim];
       end;
assign(output,'secv3.out');
rewrite(output);
writeln(s:5:2);
close(output);{
for i:=1to n do
write(t[1,i]:5:2,' ');
writeln;
for i:=1 to n do
write(t[2,i]:5:2,' ');
writeln;
for i:=1 to n do
write(t[3,i]:5:2,' ');
readkey;       }
end.