/* -*- coding: utf-8 -*-
 *
 * 1809.cc:  No.1809 Divide NCK - yukicoder
 */

#include<cstdio>
#include<cstring>
#include<vector>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_P = 1000000 + 50;
const long long LINF = 1LL << 62;

/* typedef */

typedef long long ll;
typedef pair<ll,int> pli;
typedef vector<int> vi;
typedef vector<pli> vpli;

/* global variables */

bool primes[MAX_P + 1];

/* subroutines */

int gen_primes(int maxp, vi &pnums) {
  memset(primes, true, sizeof(primes));
  primes[0] = primes[1] = false;

  int p;
  for (p = 2; p * p <= maxp; p++)
    if (primes[p]) {
      pnums.push_back(p);
      for (int q = p * p; q <= maxp; q += p) primes[q] = false;
    }
  for (; p <= maxp; p++)
    if (primes[p]) pnums.push_back(p);
  return (int)pnums.size();
}

bool prime_decomp(ll n, vi &pnums, vpli& pds) {
  pds.clear();

  int pn = pnums.size();
  for (int i = 0; i < pn; i++) {
    int pi = pnums[i];
    if ((ll)pi * pi > n) {
      if (n > 1) pds.push_back(pli(n, 1));
      return true;
    }

    if (n % pi == 0) {
      int fi = 0;
      while (n % pi == 0) n /= pi, fi++;
      pds.push_back(pli(pi, fi));
    }
  }
  return false;
}

ll fraclog(ll n, ll p) {
  ll x = 0;
  while (n > 0) {
    n /= p;
    x += n;
  }
  return x;
}

/* main */

int main() {
  vi pnums;
  int pn = gen_primes(MAX_P, pnums);
  //printf("pn=%d\n", pn);

  ll n, k, m;
  scanf("%lld%lld%lld", &n, &k, &m);

  vpli pds;
  prime_decomp(m, pnums, pds);

  ll minx = LINF;
  for (auto pd: pds) {
    ll p = pd.first;

    ll x = fraclog(n, p) - fraclog(k, p) - fraclog(n - k, p);
    x /= pd.second;

    minx = min(minx, x);
  }

  printf("%lld\n", minx);
  return 0;
}