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#include <iostream>
using namespace std;

int n, ans;

int main() {
	ios_base::sync_with_stdio(0);
	cin >> n;
	for (int i = 0, x; i < n; i++) {
		cin >> x;
		ans += x == 1 ? 1 : 0;
	}
	cout << (ans > 2 ? 0 : 2 - ans) << "\n2\n1 2";
}