import java.util.*;

public class Main {
    public static void main(String[]  args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        long total = Math.max(m - 2 * (n - 1) + 1, 0);
        ArrayList<Integer> primes = new ArrayList<>();
        primes.add(2);
        for (int i = 3; i * (n - 1) <= m; i += 2) {
            if (isPrime(i, primes)) {
                primes.add(i);
                total += m - i * (n - 1) + 1;
            }
        }
        System.out.println(total);
    }
    
    static boolean isPrime(int x, ArrayList<Integer> primes) {
        for (int y : primes) {
            if (Math.sqrt(x) < y) {
                break;
            }
            if (x % y == 0) {
                return false;
            }
        }
        return true;
    }
}