def factorize(x):
    ret = []
    p = 2
    while p * p <= x:
        cnt = 0
        while x % p == 0:
            x //= p
            cnt += 1
        if cnt:
            ret.append((p, cnt))
        p += 1
    if x > 1:
        ret.append((x, 1))
    return ret

def f(n, p):
    res = 0
    pk = p
    while pk <= n:
        res += n // pk
        pk *= p
    return res

n, k, m = map(int, input().split())
ans = min((f(n, p) - f(k, p) - f(n - k, p)) // cnt for p, cnt in factorize(m))
print(ans)