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#include <bits/stdc++.h>
using namespace std;

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