/*
 * Author: nskybytskyi
 * Time:   2022-01-13 15:08:45
 */

#include <bits/stdc++.h>
using namespace std;

int main() {
  cin.tie(0)->sync_with_stdio(0);

  int64_t n, k, m;
  cin >> n >> k >> m;

  map<int64_t, int> pp;
  for (int d = 2; d * 1ll * d <= m; ++d) {
    while (m % d == 0) {
      ++pp[d];
      m /= d;
    }
  }
  if (m > 1) {
    ++pp[m];
  }

  auto nu = [&] (int64_t x, int64_t p) -> int64_t {
    int64_t ans = 0;
    while (x) {
      ans += x / p;
      x /= p;
    }
    return ans;
  };

  auto nu2 = [&] (int64_t x, const map<int64_t, int>& pp) -> int64_t {
    int64_t mn = numeric_limits<int64_t>::max();
    for (auto [k, v] : pp) {
      mn = min(mn, nu(x, k) / v);
    }
    return mn;
  };

  cout << nu2(n, pp) - nu2(k, pp) - nu2(n - k, pp) << "\n";

  return 0;
}