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

    return arr

def f(n, p):
    val = 0
    m = p
    while n // m:
        val += n // m
        m *= p
    return val

N, K, M = map(int, input().split())
ans = 10 ** 18
for m, cnt in factorization(M):
    ans = min(ans, (f(N, m) - f(K, m) - f(N - K, m))//cnt )
print(ans)