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#include <bits/stdc++.h>

int main ()
	{
	int n, a, k=2;
	scanf ("%d",&n);
	while (n--)
		{
		scanf ("%d",&a);
		k-=(a==1);
		}
	printf ("%d\n2\n1 2\n",std::max(0,k));
	return 0;
	}