#include <bits/stdc++.h>
#define rep(i, n) for(int(i) = 0; (i) < (n); (i)++)
#define FOR(i, m, n) for(int(i) = (m); (i) < (n); (i)++)
#define ALL(v) (v).begin(), (v).end()
#define LLA(v) (v).rbegin(), (v).rend()
#define SZ(v) (v).size()
#define INT(...)                                                               \
    int __VA_ARGS__;                                                           \
    read(__VA_ARGS__)
#define LL(...)                                                                \
    ll __VA_ARGS__;                                                            \
    read(__VA_ARGS__)
#define DOUBLE(...)                                                            \
    double __VA_ARGS__;                                                        \
    read(__VA_ARGS__)
#define CHAR(...)                                                              \
    char __VA_ARGS__;                                                          \
    read(__VA_ARGS__)
#define STRING(...)                                                            \
    string __VA_ARGS__;                                                        \
    read(__VA_ARGS__)
#define VEC(type, name, size)                                                  \
    vector<type> name(size);                                                   \
    read(name)
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using Graph = vector<vector<int>>;
template <typename T> struct edge {
    int to;
    T cost;
    edge(int t, T c) : to(t), cost(c) {}
};
template <typename T> using WGraph = vector<vector<edge<T>>>;
const int INF = 1 << 30;
const ll LINF = 1LL << 60;
const int MOD = 1e9 + 7;
template <class T> inline vector<T> make_vec(size_t a, T val) {
    return vector<T>(a, val);
}
template <class... Ts> inline auto make_vec(size_t a, Ts... ts) {
    return vector<decltype(make_vec(ts...))>(a, make_vec(ts...));
}

void read() {}
template <class T> inline void read(T &a) { cin >> a; }
template <class T, class S> inline void read(pair<T, S> &p) {
    read(p.first), read(p.second);
}
template <class T> inline void read(vector<T> &v) {
    for(auto &a : v)
        read(a);
}
template <class Head, class... Tail>
inline void read(Head &head, Tail &...tail) {
    read(head), read(tail...);
}
template <class T> inline void chmax(T &a, T b) { (a < b ? a = b : a); }
template <class T> inline void chmin(T &a, T b) { (a > b ? a = b : a); }

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    LL(n, m, p);
    VEC(ll, a, n);
    map<ll, ll> use;
    sort(ALL(a));
    ll M = a[n - 1];
    auto dp = make_vec(1000, 0LL);
    rep(i, n) {
        int cnt = 0;
        ll b = a[i];
        while(b % p == 0) {
            b /= p;
            cnt++;
        }
        if(use.count(cnt)) {
            use[cnt] = max(use[cnt], b);
        } else {
            use[cnt] = b;
        }
    }
    dp[0] = 1;
    for(int i = 0; i < 1000; i++) {
        if(dp[i] >= m / M + !!(m % M))
            continue;
        for(auto [cnt, value] : use) {
            chmax(dp[i + cnt + 1], dp[i] * value);
        }
    }
    rep(i, 1000) {
        if(dp[i] >= m / M + !!(m % M)) {
            cout << i + 1 << endl;
            return 0;
        }
    }
    cout << -1 << endl;
}