#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int DY[]{1, 0, -1, 0}, DX[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1}, DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

template <typename T>
std::vector<std::pair<T, int>> prime_factorization(T n) {
  std::vector<std::pair<T, int>> res;
  for (T i = 2; i * i <= n; ++i) {
    if (n % i != 0) continue;
    int exponent = 0;
    while (n % i == 0) {
      ++exponent;
      n /= i;
    }
    res.emplace_back(i, exponent);
  }
  if (n != 1) res.emplace_back(n, 1);
  return res;
}

ll f(ll n, ll p) {
  ll res = 0, m = p;
  while (true) {
    res += n / m;
    if (m > n / p) break;
    m *= p;
  }
  return res;
}

int main() {
  ll n, k, m; cin >> n >> k >> m;
  ll ans = LINF;
  for (const auto [p, ex] : prime_factorization(m)) {
    chmin(ans, (f(n, p) - f(k, p) - f(n - k, p)) / ex);
  }
  cout << ans << '\n';
  return 0;
}