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#include "stdio.h"


int main()
{
	int		 i, k, m, n, x, t = 0;

	while (t++<1 && scanf("%d", &n)>0)
	{
		m	= 0;
		for (i=0; i<n; i++)
		{
			scanf("%d", &k);
			if (k==1)
				m++;
		}	

		x	= (m > 1) ? 0 : 2 - m;

		printf("%d\n2\n1 2\n", x);
	}

	return 0;
}