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#include <bits/stdc++.h>

using namespace std;

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int N;
  cin >> N;

  vector<int> degs(N);
  for (int &deg : degs)
    cin >> deg;

  cout << max<int>(0, 2 - (int)count(degs.begin(), degs.end(), 1)) << "\n";
  cout << "2\n1 2\n";
}