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#include <iostream>
#include <vector>

using namespace std;

int main() {
  int n;
  cin >> n;
  int buffer;
  int ones_counter = 0;
  for (int i = 0; i < n; ++i) {
    cin >> buffer;
    if (buffer == 1) {
      ones_counter++;
    }
  }
  if (ones_counter == 0) {
    cout << "2" << endl;
  } else if (ones_counter == 1) {
    cout << "1" << endl;
  } else {
    cout << "0" << endl;
  }
  cout << "2" << endl;
  cout << "1 2" << endl;
  return 0;
}