Program rrrr;
var
 i,n,j,k:word;
 str_n:string;
 b:array[1..10] of char;
 f:text;
begin
assign(f,'count.in');
reset(f);
readln(f,n);
str(n,str_n);
close(f);
b:=[];
k:=0;
str(n,str_n);
for i:=1 to length do
    if i not(in b[i]) then
    b[i]:=1;
for j:=1 to length do
  if not(b[i]=1) then k:=k+1;
assign(f,'count.out');
rewrite(f);
write(f,k);
close(f);
end.