public class CountPrime {

    public static void main(String[] args) {
        int beginInterval = 0;
        int endInterval = 100;
        int numberOfPrimes = 0;

        for(int i = beginInterval; i < endInterval; i++) {
            if(i == 2 || i == 3) {
                numberOfPrimes++;
            }

            if(i % 2 == 0 || i % 3 == 0 || i == 1) {
                continue;
            }

            int n = 5;
            boolean isPrime = true;

            while(n*n <= i) {
                if(i % n == 0 || i % (n+2) == 0) {
                    isPrime = false;
                    break;
                }
                n += 6;
            }

            if(isPrime) {
                numberOfPrimes++;
            }
        }
		System.out.println(numberOfPrimes);
    }
}