#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
#define rep(i, n) for(int i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}

int main(){
    ll m;
    vector<ll> a(3);
    cin >> a[0] >> a[1] >> m;
    ll ans = 1LL<<60, mm = m;
    a[2] = a[0] - a[1];
    map<ll,ll> mp;
    for(ll i=2;i*i<=mm;i++){
        while(!(m%i)){
            mp[i]++;
            m /= i;
        }
    }
    if(m!=1) mp[m] = 1;
    for(auto p:mp){
        //cout << p.first << " " << p.second << endl;
        auto b = a;
        ll pls = 0;
        rep(i,3){
            while(b[i]){
                b[i] /= p.first;
                if(i) pls -= b[i];
                else pls += b[i];
            }
        }
        ans = min(pls / p.second, ans);
        //cout << ans << endl;
    }
    cout << ans << endl;
    return 0;
}