import java.util.Scanner;

public class Main {
	static boolean[] isPrime;
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int N = scan.nextInt();
		int L = scan.nextInt();
		scan.close();
		int max = L / (N -1);
		isPrime = new boolean[max + 1];
		long cnt = 0;
		if(max >= 2) {
			aryPrime();
		}

		for(int i = 2; i < max + 1; i++) {
			if(isPrime[i]) {
				cnt += L - (N - 1) * i + 1;
			}
		}
		System.out.println(cnt);
	}
	static void aryPrime(){
		int l = isPrime.length;
		for(int i = 0; i < l; i++) {
			isPrime[i] = true;
		}
		isPrime[0] = false;
		isPrime[1] = false;
		for(int i = 2; i <= (int)Math.sqrt(l); i++) {
			if(isPrime[i]) {
				for(int j = i * 2; j < l; j += i) {
					isPrime[j] = false;
				}
			}
		}
	}
}