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#include <bits/stdc++.h>

using namespace std;

int main() {
#ifdef wxh010910
  freopen("input.txt", "r", stdin);
#endif
  int n;
  scanf("%d", &n);
  int m = 0;
  for (int i = 0; i < n; ++i) {
    int x;
    scanf("%d", &x);
    if (x == 1) {
      ++m;
    }
  }
  printf("%d\n2\n1 2\n", max(2 - m, 0));
  return 0;
}