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#include <iostream>
#include <algorithm>
using namespace std;

int main(){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n, x, ones=0;
	cin >> n;
	for(int i=0;i<n;i++){
		cin >> x;
		if(x==1)ones++;
	}

	cout << 2-min(2, ones) << "\n2\n1 2\n";
	return 0;
}