program xxxx;
var a:array[1..50000,0..2] of longint;
    i,n,w,x,y,r,l:longint;

function max(a1,a2:longint):longint;
begin
  if a1>a2 then
    max:=a1
  else
    max:=a2;
end;


begin
  assign(input,'groupa.in');
  reset(input);
  assign(output,'groupa.out');
  rewrite(output);
  read(n);
  for i:=1 to  n do
    begin
      read(a[i,0]);
      w:=w+a[i,0];
    end;
  read(l,r);
  if (l*n>w)or(r*n<w) then
    begin
      write('-1');
      close(input);
      close(output);
      halt;
    end;
  for i:=1 to n do
    begin
      if a[i,0]<l then
        a[i,1]:=l-a[i,0]
      else
        a[i,1]:=0;
      if a[i,0]>r then
        a[i,2]:=a[i,0]-r
      else
        a[i,2]:=0;
    end;
    x:=0;
    y:=0;
  for i:=1 to n do
    begin
      x:=x+a[i,1];
      y:=y+a[i,2];
    end;
  x:=max(x,y);
  write(x);
  close(input);
  close(output);
end.