12-4

#include<iostream.h>
int nr(int n, int c){
int i=0;
while(n!=0){
	if(n%10==c)
		i++;
	n=n/10;}
return i;}
int main(){
int n,i,y=0,x;
cin>>n;
for(i=0;i<=9;i++){
	x=nr(n,i);
	if(x!=0)
		y++;}
cout<<y;}