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

int main(){
	int n;
	cin>>n;
	int ones = 0;
	for(int i = 0; i < n; i++){
		int x;
		cin>>x;
		if(x == 1){
			ones++;
		}
	}
	cout<<(2-min(2,ones))<<endl;
	cout<<2<<endl;
	cout<<1<<" "<<2<<endl;
}