## https://yukicoder.me/problems/no/1809

import math

def calc_divisor(K, M):
    m = M
    x = K // m
    ans = x
    while x > 0:
        m *= M
        x = K // m
        ans += x
    return ans


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

    # Mを素因数分解
    primes_map = {}
    sqrt_m = int(math.sqrt(M))
    for p in range(2, sqrt_m + 1):
        if M % p == 0:
            primes_map[p] = 0
            while M % p == 0:
                M //= p
                primes_map[p] += 1
    if M > 1:
        primes_map[M] = 1

    answer = float("inf")
    for p, v in primes_map.items():
        ans1 = calc_divisor(K, p)
        ans2 = calc_divisor(N - K, p)
        ans3 = calc_divisor(N, p)
        x = ans3 - ans2 - ans1
        x0 = x // v
        answer = min(answer, x0)
    print(answer)




if __name__ == "__main__":
    main()