program grigo;
var f,g:text;
    n,m,i,nr:longint;
    a:array [1..100000] of 0..1;
    p:int64;

begin
 assign (F,'grigo.in'); reset (f);
 assign (g,'grigo.out'); rewrite (g);
 readln (F,n,m);
 for i:=1 to m do
 begin
  read (f,nr);
  a[nr]:=1;
 end;
 p:=1;
 for i:=1 to n do
  if a[i]=0 then
   p:=(p*(i-1)) mod 1000003;
  write (g,p);
 close (f); close (g);
end.