#include <iostream>
#include <fstream>

using namespace std;
ifstream r("cfdist.in");
ofstream w("cfdist.out");

bool v[10];

int main()
{
    int n,  a=0, b, i=9;
    r>>n;
    while(n!=0){
        b=n%10;
        v[b]=1;
        n=n/10;
    }
    while(i>=0){
        if(v[i]==1){
            a+=1;
        }
        i=i-1;
    }
    w<<a;
    return 0;
}