#include <iostream>

int main() {
    long long n;
    std::cin >> n;
    long long ans = n;
    for (long long d = 1; d * d <= n; ++d) {
        if (n % d == 0) {
            ans -= 1 + (d * d != n);
        }
    }
    std::cout << ans << std::endl;
}