1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
#include <iostream>
using namespace std;

int main() {
	int n;
	cin >> n;
	int j=0;
	for (int i=0;i<n;i++) {
		int a;
		cin >> a;
		if (a==1) j++;
	}
	cout << (j>1 ? 0 : 2-j) << endl;
	cout << 2 << endl;
	cout << "1 2";
	return 0;
}