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#include<bits/stdc++.h>

#define luk(n,m) for(int i=n; i<m; ++i)
#define maxn 2000010
#define pb(n) push_back(n)
#define mp make_pair
#define inf 1000000000
#define mod 1000000007
#define ll long long
#define ff first.first
#define fs first.second



using namespace std;



int main()
{
	int n,a;
	int ile=0;
	scanf("%d", &n);
	luk(0,n)
	{
		scanf("%d", &a);
		if((ile==1||ile==0)&&a==1)
			++ile;
	}
	if(ile==2)
		printf("0\n");
	if(ile==1)
printf("1\n");
if(ile==0)
printf("2\n");

	printf("2\n");
	printf("1 2");
	
}