import java.io.*; import java.util.*; public class Main { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = sc.nextInt(); int length = sc.nextInt(); boolean[] isNotPrime = new boolean[length / 2 + 2]; long ans = 0; for (int i = 2; i < isNotPrime.length && i * (n - 1) <= length; i++) { if (!isNotPrime[i]) { ans += length - i * (n - 1) + 1; for (int j = 2; j * i < isNotPrime.length; j++) { isNotPrime[j * i] = true; } } } System.out.println(ans); } } class Scanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); public Scanner() throws Exception { } public int nextInt() throws Exception { return Integer.parseInt(next()); } public long nextLong() throws Exception { return Long.parseLong(next()); } public double nextDouble() throws Exception { return Double.parseDouble(next()); } public String next() throws Exception { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }