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#include <cstdio>

int main()
{
	int n, x;
	scanf("%d", &n);
	int ones = 0;
	for (; n > 0 && ones < 2; n--)
	{
		scanf("%d", &x);
		ones += x == 1;
	}
	printf("%d\n2\n1 2\n", 2 - ones);
	return 0;
}