program z1;

{$APPTYPE CONSOLE}

var f1,f2:text;
    a,b,n,i,j:integer;
    ma:array [0..9] of integer;
    ch:char;

begin
assign(f1,'count.in');
assign(f2,'count.out');
reset(f1);
while not eof(f1) do
 begin
 read(f1,ch);
 if ch='0' then ma[0]:=1 else
 if ch='1' then ma[1]:=1 else
 if ch='2' then ma[2]:=1 else
 if ch='3' then ma[3]:=1 else
 if ch='4' then ma[4]:=1 else
 if ch='5' then ma[5]:=1 else
 if ch='6' then ma[6]:=1 else
 if ch='7' then ma[7]:=1 else
 if ch='8' then ma[8]:=1 else
 if ch='9' then ma[9]:=1;
 end;
close(f1);
rewrite(f2);
for i:=0 to 9 do n:=n+ma[i];
writeln(f2,n);
close(f2);
end.