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#include <bits/stdc++.h>
using namespace std;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(NULL); cout.tie(NULL);
	int n; cin>>n; int lp = 0;
	for(int i = 0; i < n; i++)
	{
		int x; cin>>x;
		if(x==1) lp++;
	}
	if(lp>=2)
		cout<<0;
	else if(lp==1)
		cout<<1;
	else
		cout<<2;
	cout<<"\n2\n1 2";
}