import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import numpy as np

N,L = map(int,read().split())

U = 10 ** 7
is_prime = np.zeros(U,np.bool_)
is_prime[2] = 1
is_prime[3::2] = 1
for p in range(3,U,2):
    if p*p >= U:
        break
    if is_prime[p]:
        is_prime[p*p::p+p] = 0

primes = np.where(is_prime)[0]
D = primes * (N-1)
answer = np.maximum(0, L - D + 1).sum()
print(answer)