#include <iostream>
#include <set>
#include <cmath>


bool isPrime2(int num) {
    if(num == 1) return false;
    int sprt = std::sqrt(num);
    int del = 2;
    if (num % del == 0) return false;
    del++;
    while (del <= sprt) {
        if(num % del == 0) return false;
        del += 2;
    }
    return true;
}

int main() {
    std::string numStr;
    std::cin >> numStr;

    int cnt = 0;

    while (true) {
        cnt += isPrime2(atoi(numStr.c_str()));

        if(numStr.size() == 1) break;

        numStr = numStr.substr(1);

        while (numStr[0] == '0')
            numStr = numStr.substr(1);

    }

    std::cout << cnt << std::endl;

    return 0;
}