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();
        int length = m / (n - 1) + 1;
        boolean[] isPrime = new boolean[length];
        isPrime[0] = true;
        isPrime[1] = true;
        long total = 0;
        for (int i = 2; i * (n - 1) <= m; i++) {
            if (!isPrime[i]) {
                total += m - i * (n - 1) + 1;
                for (int j = i * 2; j < length; j += i) {
                    isPrime[j] = true;
                }
            }
        }
        System.out.println(total);
    }
}