def prime_factorization(n):  # 素因数分解
    res = []
    for i in range(2, int(n ** 0.5) + 1):
        if n % i == 0:
            cnt = 0
            while n % i == 0:
                cnt += 1
                n //= i
            res.append((i, cnt))
    if n > 1:
        res.append((n, 1))
    return res


def count(N, p):
    """N!がpで何回割れるか"""
    res = 0
    v = 1
    for _ in range(100):
        v *= p
        if v > N:
            break
        res += N // v
    return res


N, K, M = map(int, input().split())
pf = prime_factorization(M)
X = 10 ** 18
for p, f in pf:
    tot = count(N, p) - count(K, p) - count(N - K, p)
    X = min(X, tot // f)
print(X)