//
// Created by cteam37 on 10/19/24.
//


#include <iostream>
#include <math.h>
#include <set>

using namespace std;

bool isPrime(int num){
    if(num < 2) return false;
    for(size_t i = 2; i < num; i++) {
        if(num%i == 0) {
            return false;
        }
    }
    return true;
}

set<int> Primes (string input) {
    if(input.empty()) return {};
    set<int> maxPrimes = {};
    for (int i = 0; i < input.size(); ++i) {
        string tmp;
        for (int j = 0; j < input.size(); ++j) {
            if(j==i) continue;
            tmp += input[j];
        }
        set<int> primes = Primes(tmp);
        if(primes.size() > maxPrimes.size()) maxPrimes = primes;
    }
    if(isPrime(stoi(input))) {
        maxPrimes.insert(stoi(input));
        return maxPrimes;
    }
    return {};
}

int main() {
    int i;
    cin >> i;
    string input = to_string(i);

    auto primes = Primes(input);
    cout << primes.size() << endl;

    return 0;
}