program z1;
           uses crt;
           var a:array[1..1000000] of char;
           b:array[1..1000000]of word;
           s:string;
           n,k,j:longint;
           i,o:text;
           rez:longint;
           begin
           assign(i,'D:\count.in');
           reset(i);
           read(i,s);
           close(i);
           n:=length(s);
           for k:=1 to n do
           a[k]:=s[k];
           for k:=1 to n do begin
           for j:=1 to n do
           if a[k]<>a[j] then b[k]:=1;
           end;
           for k:=1 to n do
           rez:=rez+b[k];
           assign(o,'D:\count.out');
           rewrite(o);
           writeln(o,rez);
           close(o);
           end.