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#include <iostream>
using namespace std;

int main()
{
  int n,x;
  cin >> n;
  int number_of_ones = 0;
  for (int i = 0; i < n; ++i) {
    cin >> x;
    number_of_ones += (x==1);
  }
  if (number_of_ones >= 2) number_of_ones = 2;
  cout << 2 - number_of_ones << "\n2\n1 2\n";
  return 0;
}