#include <bits/stdc++.h>
using namespace std;
long int hcf(long int x, long int y) {
  if (x == 0) return 1;
  if (y % x == 0) {
    return x;
  }
  return hcf(y % x, x);
}
int main() {
  int i, n, k = 0;
  cin >> n;
  long int a[1005], pos[1005] = {-1}, temp;
  cin >> a[0];
  for (i = 1; i < n; i++) {
    cin >> a[i];
    if (a[i] < a[i - 1])
      temp = hcf(a[i], a[i - 1]);
    else
      temp = hcf(a[i - 1], a[i]);
    if (temp != 1) {
      pos[k++] = i;
    }
  }
  cout << k << "\n";
  int j = 0;
  for (i = 0; i < n; i++) {
    if (pos[j] == i) {
      cout << "1 ";
      j++;
    }
    cout << a[i] << " ";
  }
  return 0;
}
