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#include <cstdio>

int n,x,count = 0;

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