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

def factorization(n):
    res = []
    s = 2
    while s*s<=n:
        if n%s==0:
            cnt = 0
            while n%s==0:
                n//=s
                cnt+=1
            res.append([s, cnt])
        s+=1
    if n>1:
        res.append([n, 1])
    return res

def prime_num(N, p):
    res = 0
    while N>=p:
        N//=p
        res+=N
    return res

res = factorization(M)
ans = float('inf')
for p, cnt in res:
    # ans = min(ans, prime_num(N, pow(p, cnt))-prime_num(N-K, pow(p, cnt))-prime_num(K, pow(p, cnt)))
    ans = min(ans, (prime_num(N, p)-prime_num(N-K, p)-prime_num(K, p))//cnt)
print(ans)