#include using namespace std; using ll = long long; using ld = long double; using VI = vector; using VL = vector; using VS = vector; template using PQ = priority_queue, greater>; #define FOR(i,a,n) for(int i=(a);i<(n);++i) #define eFOR(i,a,n) for(int i=(a);i<=(n);++i) #define rFOR(i,a,n) for(int i=(n)-1;i>=(a);--i) #define erFOR(i,a,n) for(int i=(n);i>=(a);--i) #define SORT(a) sort(a.begin(),a.end()) #define rSORT(a) sort(a.rbegin(),a.rend()) #define fSORT(a,f) sort(a.begin(),a.end(),f) #define all(a) a.begin(),a.end() #define out(y,x) ((y)<0||h<=(y)||(x)<0||w<=(x)) #define tp(a,i) get(a) #ifdef _DEBUG #define line cout << "-----------------------------\n" #define stop system("pause") #define debug(x) print(x) #endif constexpr ll INF = 1000000000; constexpr ll LLINF = 1LL << 60; constexpr ll mod = 1000000007; constexpr ll MOD = 998244353; constexpr ld eps = 1e-10; constexpr ld pi = 3.1415926535897932; templateinline bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; }return false; } templateinline bool chmin(T& a, const T& b) { if (a > b) { a = b; return true; }return false; } inline void init() { cin.tie(nullptr); cout.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); } templateinline istream& operator>>(istream& is, vector& v) { for (auto& a : v)is >> a; return is; } templateinline istream& operator>>(istream& is, pair& p) { is >> p.first >> p.second; return is; } templateinline vector vec(size_t a) { return vector(a); } templateinline vector defvec(T def, size_t a) { return vector(a, def); } templateinline auto vec(size_t a, Ts... ts) { return vector(ts...))>(a, vec(ts...)); } templateinline auto defvec(T def, size_t a, Ts... ts) { return vector(def, ts...))>(a, defvec(def, ts...)); } templateinline void print(const T& a) { cout << a << "\n"; } templateinline void print(const T& a, const Ts&... ts) { cout << a << " "; print(ts...); } templateinline void print(const vector& v) { for (int i = 0; i < v.size(); ++i)cout << v[i] << (i == v.size() - 1 ? "\n" : " "); } templateinline void print(const vector>& v) { for (auto& a : v)print(a); } inline string reversed(const string& s) { string t = s; reverse(all(t)); return t; } templateinline T sum(const vector& a, int l, int r) { return a[r] - (l == 0 ? 0 : a[l - 1]); } templateinline void END(T s) { print(s); exit(0); } void END() { exit(0); } ll m; VL cost(31, -1); map dp; int solve(ll x) { if (dp.count(x))return dp[x]; int ans = INF; eFOR(i, 1, 30) { if (cost[i] == -1)continue; if (x * cost[i] > m)ans = i; else chmin(ans, solve(x * cost[i]) + i); } return dp[x] = ans; } int main() { init(); int n; ll p; cin >> n >> m >> p; VL a(n); cin >> a; VI b(n, 1); bool ng = true; FOR(i, 0, n) { while (a[i] % p == 0) { a[i] /= p; ++b[i]; } if (1 < a[i])ng = false; } if (ng)END(-1); FOR(i, 0, n)if (a[i] != 1)chmax(cost[b[i]], a[i]); print(solve(1)); return 0; }