from math import sqrt

def solve():
    n, l = map(int, input().split())
    ans = 0
    primes = [True for _ in range(l)]
    primes[0], primes[1] = False, False
    for i in range(2, int(sqrt(l)) + 1):
        if primes[i]:
            for j in range(2, l // i - 1):
                primes[i * j] = False

    for i in range(2, l):
        if primes[i]:
            t = (l + 1) - (n - 1) * i
            if t <= 0:
                break
            ans += t
    print(ans)

if __name__=="__main__":
    solve()