var n,i,i1,i2,s,b:int64;
sort,pro:array [1..100000] of int64;
begin
  readln(n);
  b:=1;
  s:=n;
  for i:=1 to n do
    read(sort[i]);
  for i:=1 to n do
    for i1:=i+1 to n do
      if sort[i]=sort[i1]
        then
          begin
            s:=s-1;
            sort[i]:=10000000000-2000+i;
          end;


  writeln(s);
end.