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#include <iostream>
#include <algorithm>

using namespace std;
int main()
{
	ios::sync_with_stdio(false);
	int numberOfOnes = 0, n, tmp;
	cin >> n;

	while(n--)
	{
		cin >> tmp;
		if(tmp == 1)
		{
			++numberOfOnes;
		}
	}

	cout << std::max(0, 2 - numberOfOnes) << "\n2\n1 2\n";
	return 0;
}