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#include<iostream>
using namespace std;
int main(){
  int n, j = 0, t;
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n;
  for(int i = 0;i < n;i++){
    cin >> t;
    if(t == 1)
      j++;
  }
  cout << max(0, 2 - j) << "\n2\n1 2\n";
}