#嘘解法

N,K,M = map(int,input().split())

def prime_factorize(n):
	prime = []
	f = 2
	while(f * f <= n):
		if(n % f == 0):
			n //= f
			cnt = 1
			while(n % f == 0):
				n //= f
				cnt += 1
			prime.append((f,cnt))
		else:
			f += 1
	if(n != 1):
		prime.append((n,1))
	return prime

def legendre(N,K,p,q):
	R = N - K
	cnt = c = 0
	p *= q
	while(N):
		N //= p
		cnt += N
	while(K):
		K //= p
		cnt -= K
	while(R):
		R //= p
		cnt -= R
	return cnt

prime = prime_factorize(M)
ans = 10 ** 18
for p,c in prime:
	cnt = legendre(N,K,p,c)
	if(ans > cnt):
		ans = cnt

print(ans)