program A;
uses SysUtils;
var FIn : TextFile;
FOut : TextFile;
Line : String;
Count : Integer;
Arr : array  of Boolean;
LengthLn : Integer;
StartLn : Integer;
Char : String;
CountAll : Integer;
CountFirstArr : Integer;
CopyLen : Integer;
begin
assign(FIn,'count.in');
reset(FIn);
readLn(FIn,Line);
close(FIn);
LengthLn := Length(Line);
StartLn := 1;
CountFirstArr := 1;
while CountFirstArr <= LengthLn do
begin
  Arr[CountFirstArr]:=False;
  CountFirstArr := CountFirstArr + 1;
end;
CopyLen := 1;
while StartLn<=LengthLn do
begin
  Char := copy(Line,StartLn,CopyLen);
  if StrToInt(Char)=9 then CopyLen:= 2 else
  if StrToInt(Char)=99 then CopyLen:= 3 else
  if StrToInt(Char)=999 then CopyLen:= 4;
  Arr[StrToInt(Char)] := True;
  StartLn := StartLn+1;
end;
CountAll := 0;
CountFirstArr :=1;
while CountFirstArr <= LengthLn do
begin
  if Arr[CountFirstArr]=True then CountAll:=CountAll+1;
  CountFirstArr := CountFirstArr + 1;
end;
Assign(FOut,'count.out');
Rewrite(FOut);
WriteLn(FOut,CountAll);
Close(FOut);
end.