program task_a;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var

  f:text;
  s:ansistring;
  a:array['0'..'9'] of integer;
  ans:integer;
  i:longint;
  c:char;
begin
fillchar(a,sizeof(a),0);
assign(f,'count.in');
reset(f);
readln(f,s);

close(f);
for i:=1 to length(s) do a[s[i]]:=1;

for c:='0' to '9' do ans:=ans+a[c];

assign(f,'count.out');
rewrite(f);
writeln(f,ans);
close(f);
end.