def make_prime_table(n):
    sieve = list(range(max(n + 1, 2)))
    sieve[0] = -1
    sieve[1] = -1
    for i in range(4, n + 1, 2):
        sieve[i] = 2
    for i in range(3, int(n ** 0.5) + 1, 2):
        if sieve[i] != i:
            continue
        for j in range(i * i, n + 1, i * 2):
            if sieve[j] == j:
                sieve[j] = i
    return sieve


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

t = L // (N - 1)
result = 0
table = make_prime_table(t)
for i in range(2, t + 1):
    if table[i] != i:
        continue
    result += L - i * (N - 1) + 1
print(result)