var  n,i,j,k,m,min,max,l,r:longint;
     a:array[0..51]of int64;
     tot,s:int64;
begin
assign(input,'groupa.in');reset(input);
assign(output,'groupa.out');rewrite(output);
readln(n);
tot:=0; s:=0;
for i:=1 to n do
  begin
  read(a[i]);tot:=tot+a[i];
  end;
readln(l,r);
if (tot div n <l)or(tot div n>r) then
  begin writeln('-1');close(input);close(output);halt;   end;
tot:=0;  s:=0;
for i:=1 to n do
 begin
 if a[i]<l then tot:=tot+l-a[i];
 if a[i]>r then s:=s+a[i]-r;

 end;
if tot<s then tot:=s;
writeln(tot);


close(input);close(output);

end.