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#include <iostream>

using namespace std;

int main(void) {
  int n, i, c = 0;

  cin >> n;
  while (n-- > 0) {
    cin >> i;
    if (i == 1) c++;
  }

  cout << (c > 1 ? 0 : c == 1 ? 1 : 2) << endl
       << 2 << endl
       << 1 << ' ' << 2;

  return 0;
}