n, p = map(float, input().split())
n = int(n)

primes = set(range(2, n + 1))
A = set(range(2, n + 1))


def prf(m):
    pf = {}
    for i in range(2, int(m ** 0.5) + 1):
        while not m % i:
            pf[i] = pf.get(i, 0) + 1
            m //= i
    if m > 1:
        pf[m] = 1
    return pf


for i in range(2, int(n ** 0.5 + 1)):
    if i not in primes:
        i += 1
    else:
        ran = range(i * 2, n + 1, i)
        primes.difference_update(ran)
pn = len(list(primes))
B = list(A.difference(primes))

res = pn
for b in B:
    tmp = prf(b)
    e = [max(0, i - 2) for i in tmp.values()]
    res += p ** (len(tmp) + sum(e))
print(res)