program Project2;
{$APPTYPE CONSOLE}
uses
  SysUtils;

var inp,outp: text;
    a: array[1..100000]of AnsiString;
    i,j,ans: longint;
    c: char;
    s: string;
begin
   assign(inp,'count.in');
   assign(outp,'count.out');
   reset(inp);
   rewrite(outp);
   ans:=0;
   s:='';
   while not eoln(inp)do
      begin
         read(inp,c);
         if pos(c,s)<>0 then
            begin
               s:=s+c;
               inc(ans);
            end;
      end;
   writeln(outp,ans);
   close(inp);
   close(outp);
end.