program groupa;
var a,b,tot:int64;
    g:array[1..100]of longint;
    l,r,t,k,m,n,i,j:longint;
begin
assign(input,'groupa.in');
reset(input);
assign(output,'groupb.out');
rewrite(output);
readln(n);
for t:=1 to n do
  begin
    read(g[t]);
    tot:=tot+g[t];
  end;
readln;
readln(l,r);
if (tot div n<l)or(tot div n>r)or(tot div n=r)and(tot mod n>0) then
  begin
    writeln(-1);
    close(output);
    halt;
  end;
for t:=1 to n do
  begin
    if g[t]<l then a:=a+l-g[t]
    else if g[t]>r then b:=b+g[t]-r;
  end;
if a>b then writeln(a)
else writeln(b);
close(output);
end.