/CHAR - Đếm ký tự

              USES CRT;
        var     s,s1:string;
                i,dem:int32;
                begin
                    readln(s);
                    for i:=1 to length(s) do begin
                        if pos(s[i],s1)=0 then s1:=s1+s[i];
                    end;
                    writeln(length(s1));
                end.