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#include <cstdio>

using namespace std;

int main() {
  int n;
  scanf("%d", &n);
  int cnt1 = 0;
  for (int i = 0; i < n; ++i) {
    int d;
    scanf("%d",&d);
    cnt1 += (d == 1);
  }
  if (cnt1 > 2) {
    cnt1 = 2;
  }
  printf("%d\n2\n1 2\n", 2 - cnt1);
  return 0;
}