def count(x, p):
    res = 0
    v = p
    while v <= x:
        res += x // v
        v *= p
    return res


def factorization(n):
    if n == 1:
        return [[1, 1]]
    tmp = n
    res = []
    for i in range(2, int(n ** 0.5 + 1.01)):
        if tmp % i == 0:
            cnt = 0
            while tmp % i == 0:
                tmp //= i
                cnt += 1
            res.append([i, cnt])
    if tmp != 1:
        res.append([tmp, 1])
    return res


N, K, M = map(int, input().split())
primes = factorization(M)
ans = 1 << 60
for p, c in primes:
    v = count(N, p) - count(N - K, p) - count(K, p)
    ans = min(ans, v // c)

print(ans)