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

using namespace std;

bool isPrime(long long n) {
        if (n == 1) return false;
        for (int i = 2; i <= sqrt(n); i++) {
                if (n%i == 0) return false;
        }
        return true;
}
int main() {
        int a1, a2, N, res = 0, tmp;

        cin >> a1 >> a2 >> N;

        if (isPrime(a1)) res++;
        if (isPrime(a2)) res++;

        for (int i = 0; i < N-2; i++) {
                tmp = (a1 + a2) % 1000002014;
                if (isPrime(tmp)) res++;
                a1 = a2;
                a2 = tmp;
        }
        cout << res;
        return 0;
}