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#include <cstdio>

using namespace std;

int n, ones_amount;

int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; ++i) {
    int x;
    scanf("%d", &x);
    if (x == 1) {
      ++ones_amount;
    }
  }
  if (ones_amount >= 2) {
    printf("0\n");
  } else if (ones_amount == 1) {
    printf("1\n");
  } else {
    printf("2\n");
  }
  printf("2\n");
  printf("1 2\n");
  return 0;
}