#include <bits/stdc++.h>
using namespace std;
<<<<<<< HEAD
int main() {
    
=======
const int INF = 0x3f3f3f3f;
const int N = 1010;
struct Node {
    int number;
    int count;
} a[N];
int al;
int m1;
int m2;
int n;
int mi = INF;
int main() {
    cin >> n >> m1 >> m2;
    for (int i = 2; i <= m1; i++) {
        if (m1 % i == 0) {
            a[++al].number = i;
            while (m1 % i == 0) {
                a[++al].count++;
            }
            a[al].count *= m2;
        }
    }
    while (n--) {
        int s;
        cin >> s;
        bool flag = true;
        for (int i = 1; i <= al; i++)
            if (s % a[i].number != 0) {
                flag = false;
                break;
            }
        if (flag) {
            int mx = 0;
            for (int i = 1; i <= al; i++) {
                int cnt = 0;
                while (s % a[i].number == 0) {
                    s /= a[i].number;
                    cnt++;
                }
                int second = ceil(1.0 * a[i].count / cnt);
                mx = max(mx, second);
            }
            mi = min(mi, mx);
        }
    }
    if (mi == INF) printf("-1");
    else printf("%d", mi);
>>>>>>> 485a3e402b5262a90312e541a18a7485bc87f84d
    return 0;
}