import sys, os, io
input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline
m = int(input())
s = list(map(int, input().split()))
s.sort()
s0 = s[0]
ok = 1
for i in s:
if i % s0:
ok = 0
if not ok:
ans = -1
print(ans)
exit()
ans = []
for i in s:
ans.append(i)
ans.append(s0)
m = len(ans)
print(m)
sys.stdout.write(" ".join(map(str, ans)))#include <bits/stdc++.h>
using namespace std;
#define fastio ios_base::sync_with_stdio(false); cout.tie(NULL);
#define int long long
using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
const int INF = 0x3f3f3f3f;
void debug(set<int> s) {
for (int i : s) {
cout << i << " ";
}
cout << endl;
}
void debug(unordered_set<int> s) {
for (int i : s) {
cout << i << " ";
}
cout << endl;
}
void debug(vector<string> s) {
for (string i : s) {
cout << i << " ";
}
cout << endl;
}
void debug(vector<pii> v) {
cout << "PAIR START" << endl;
for (auto i : v) {
cout << i.first << " " << i.second << endl;
}
cout << "PAIR END" << endl;
}
void debug(vector<int> v) {
for (int i : v) {
cout << i << " ";
}
cout << endl;
}
void debug(map<int, int> v) {
cout << "PAIR START" << endl;
for (auto i : v) {
cout << i.first << " " << i.second << endl;
}
cout << "PAIR END" << endl;
}
void debug(vector<vector<int>> adj) {
for (vector<int> i : adj) {
for (int j : i) {
cout << j << " ";
}
cout << endl;
}
}
void iohelp(string s) {
ios_base::sync_with_stdio(0); cin.tie(0);
freopen((s+".in").c_str(),"r",stdin);
freopen((s+".out").c_str(),"w",stdout);
}
ll max(ll a, ll b) {
return a > b ? a : b;
}
ll min(ll a, ll b) {
return a < b ? a : b;
}
ll gcd(ll a, ll b) {
ll temp = min(a, b);
a = max(a, b);
b = temp;
return b == 0 ? a : gcd(b, a % b);
}
int32_t main() {
fastio;
int n;
cin >> n;
vi v(n);
set<int> s;
for (int i = 0; i < n; ++i) {
cin >> v[i];
s.insert(v[i]);
}
int g = v[0];
for (int i = 0; i < n; ++i) {
if (v[i] % g != 0) {
cout << -1 << endl;
return 0;
}
}
cout << 2 * n - 1 << endl;
for (int i = 0; i < n; ++i) {
cout << v[i] << " ";
if (i != n - 1) {
cout << g << " ";
}
}
cout << endl;
}238. Product of Array Except Self | 229. Majority Element II |
222. Count Complete Tree Nodes | 215. Kth Largest Element in an Array |
198. House Robber | 153. Find Minimum in Rotated Sorted Array |
150. Evaluate Reverse Polish Notation | 144. Binary Tree Preorder Traversal |
137. Single Number II | 130. Surrounded Regions |
129. Sum Root to Leaf Numbers | 120. Triangle |
102. Binary Tree Level Order Traversal | 96. Unique Binary Search Trees |
75. Sort Colors | 74. Search a 2D Matrix |
71. Simplify Path | 62. Unique Paths |
50. Pow(x, n) | 43. Multiply Strings |
34. Find First and Last Position of Element in Sorted Array | 33. Search in Rotated Sorted Array |
17. Letter Combinations of a Phone Number | 5. Longest Palindromic Substring |
3. Longest Substring Without Repeating Characters | 1312. Minimum Insertion Steps to Make a String Palindrome |
1092. Shortest Common Supersequence | 1044. Longest Duplicate Substring |
1032. Stream of Characters | 987. Vertical Order Traversal of a Binary Tree |