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

#define int long long
#define REP(i,m,n) for(int i=(m);i<(n);i++)
#define rep(i,n) REP(i,0,n)
#define pb push_back
#define all(a) a.begin(),a.end()
#define rall(c) (c).rbegin(),(c).rend()
#define mp make_pair
#define endl '\n'
//#define vec vector<ll>
//#define mat vector<vector<ll> >
#define fi first
#define se second
#define double long double
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll> pll;
//typedef long double ld;
typedef complex<double> Complex;
const ll INF=1e9+7;
const ll MOD=998244353;
const ll inf=INF*INF;
const ll mod=MOD;
const ll MAX=100010;
const double PI=acos(-1.0);
typedef vector<vector<ll> > mat;
typedef vector<ll> vec;


void solve(){
    ll x=0;
    ll n,k,m;
    cin>>n>>k>>m;
    vector<pll>p(0);
    ll z=m;
    for(int i=2;i*i<=m;i++){
        if(z%i)continue;
        ll cnt=0;
        while(z%i==0){
            z/=i;
            cnt++;
        }
        p.pb(mp(i,cnt));
    }
    if(z>1)p.pb(mp(z,1));
    ll y=p.size();
    vector<ll>q(y);
    ll mi=inf;
    rep(i,y){
        ll cop=n;
        while(cop){
            q[i]+=cop/p[i].fi;
            cop/=p[i].fi;
        }
        cop=n-k;
        while(cop){
            q[i]-=cop/p[i].fi;
            cop/=p[i].fi;
        }
        cop=k;
        while(cop){
            q[i]-=cop/p[i].fi;
            cop/=p[i].fi;
        }
        mi=min(mi,q[i]/p[i].se);
    }
    cout<<mi<<endl;
}

signed main(){
    //cin.tie(0);
    //ios::sync_with_stdio(false);
    solve();
}