package main

import (
	"fmt"
	"math"
)

func isPrime(n int) bool {
	if n & 1 == 0 && n != 2 {
		return false
	}
	for i := 3; i <= int(math.Sqrt(float64(n))); i += 2 {
		if n % i == 0 {
			return false
		}
	}
	return true
}

func main() {
	var n, l, ans int
	fmt.Scan(&n, &l)
	for i := 2; i <= (l+1)/(n-1); i++ {
		if isPrime(i) {
			ans += l - (i * (n-1)) + 1
		}
	}
	fmt.Println(ans)
}