#include <iostream>
#include <vector>
#include <map>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> P;

const ll INF = 1000000000000000000;

std::vector<int> enum_prime(int n){     // containing n
    std::vector<int> res;
    if (n <= 1) return res;
    std::vector<bool> p(n + 1);
    fill(p.begin() + 2, p.end(), true);
    for(int i = 2; i <= n; i++){
        if(p[i]){
            res.push_back(i);
            for(int j = i * 2; j <= n; j += i) p[j] = false;
        }
    }
    return res;
}

int main()
{
    ll n, k, m;
    cin >> n >> k >> m;
    vector<int> prime = enum_prime(1000000);
    map<ll, ll> mp;
    for(ll p : prime){
        if(m % p == 0){
            while(m % p == 0){
                mp[p]++;
                m /= p;
            }
        }
    }
    if(m > 1) mp[m] = 1;
    ll ans = INF;
    for(P q : mp){
        ll p = q.first;
        ll c = 0;
        ll t;
        t = n;
        while(t){
            t /= p;
            c += t;
        }
        t = k;
        while(t){
            t /= p;
            c -= t;
        }
        t = n - k;
        while(t){
            t /= p;
            c -= t;
        }
        ans = min(ans, c / q.second);
    }
    cout << ans << endl;
}