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#ifdef _MSC_VER
  #ifndef __GNUC__
    #pragma warning(disable: 4996)
  #endif
  #define main main0
#endif
#include <iostream>
using namespace std;

int main() {
  ios_base::sync_with_stdio(0);
  //cin.tie(NULL);
  int n, k, result = 2;
  cin >> n;
  for(int i = 0; i < n; ++i) {
    cin >> k;
    if(k == 1)
      if(--result == 0)
        break;
  }
  cout << result << '\n' << "2\n1 2" << endl;
  return 0;
}