#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(v) v.begin(),v.end()
typedef long long ll;
 
#include<bits/stdc++.h>
using namespace std;

#include <boost/multiprecision/cpp_dec_float.hpp>
#include <boost/multiprecision/cpp_int.hpp>
namespace mp = boost::multiprecision;
using Bint = mp::cpp_int;

map<Bint,Bint> prime_factor(Bint x){
  map<Bint,Bint> res;
  
  for(Bint i=2;i*i<=x;i++){
    while(x%i==0){
      res[i]++;
      x/=i;
    }
  }
  if(x!=1) res[x]++;
  
  return res;
}
 
int main(){
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  
  Bint n,k,m;
  cin>>n>>k>>m;
  
  map<Bint,Bint> M=prime_factor(m);
  
  Bint ans=1000000000000000000;
  for(auto [a,b]:M){
    Bint sum=0;
    Bint t=a;
    while(n/t>=1){
      sum+=n/t;
      t*=a;
    }
    t=a;
    while(k/t>=1){
      sum-=k/t;
      t*=a;
    }
    t=a;
    while((n-k)/t>=1){
      sum-=(n-k)/t;
      t*=a;
    }
    ans=min(ans,sum/b);
  }
  cout<<ans<<endl;
  
  return 0;
}