#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <cmath>
#include <map>
#include <queue>
#include <iomanip>
#include <set>
#include <tuple>
#define mkp make_pair
#define mkt make_tuple
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define all(v) v.begin(),v.end()
using namespace std;
typedef long long ll;
const ll MOD=1e9+7;
template<class T> void chmin(T &a,const T &b){if(a>b) a=b;}
template<class T> void chmax(T &a,const T &b){if(a<b) a=b;}

const ll INF=1e18;

const int LIM=2e3;

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  ll N,M,P;
  cin>>N>>M>>P;
  vector<ll> A(N);
  rep(i,N) cin>>A[i];

  vector<int> B(N);
  vector<ll> C(N);
  rep(i,N){
    int num=0;
    int val=A[i];
    while(val%P==0){
      val/=P;
      num++;
    }
    B[i]=val;C[i]=num;
  }

  ll ma=*max_element(all(A));

  vector<ll> dp(LIM+1,0);
  dp[0]=1;
  for(int i=0;i<LIM;i++){
    if(dp[i]*ma>M){
      cout<<i+1<<endl;
      return 0;
    }
    if(dp[i]==0) continue;

    ll value=dp[i];
    for(int j=0;j<N;j++){
      if(i+C[j]+1<=LIM) chmax(dp[i+C[j]+1],value*B[j]);
    }
  }

  cout<<-1<<endl;



  return 0;
}