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#include<bits/stdc++.h>
using namespace std;
int n, x, l;
int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin>>n;
	for (int i=0; i<n; i++)
	{
		cin >>x;
		if (x==1)
		l++;
	}
	if (l==0)cout<<2<<"\n";
	else if (l==1)cout<<1<<"\n";
	else cout<<0<<"\n";
	cout <<2<<"\n"<<1<<" "<<2<<"\n";
}