#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#include <cmath>
#include <algorithm>
#include <functional>
using namespace std;
#define rep(i,n) for(int i=0;i<(n);++i)
#define rep1(i,n) for(int i=1;i<=(n);++i)
#define all(c) (c).begin(),(c).end()
#define pb push_back
#define fs first
#define sc second
#define show(x) cout << #x << " = " << x << endl
int main(){
	int n,c[2]={};
	vector<int> a,ans;
	cin>>n;
	rep(i,n){
		int d;
		cin>>d;
		if(d>=2) a.pb(d);
		else c[d]++;
	}
	sort(all(a),greater<int>());
	if(c[1]==0&&c[0]%2==1){
		if(a.size()==0){
			rep(i,c[0]) cout<<0<<endl;
			return 0;
		}else{
			int mn=a[a.size()-1];
			c[min(1,mn)]--;
			a.erase(a.end()-1);
			ans.pb(0);
			ans.pb(mn);
			rep(i,c[0]-1) ans.pb(0);
		}
	}else if(c[0]%2==0){
		rep(i,c[1]) ans.pb(1);
		rep(i,c[0]) ans.pb(0);
	}else{
		rep(i,c[1]-1) ans.pb(1);
		ans.pb(0);
		ans.pb(1);
		rep(i,c[0]-1) ans.pb(0);
	}
	if(a.size()<=1){
		rep(i,a.size()) ans.pb(a[i]);
	}else{
		if(a[0]==3&&a[1]==2) swap(a[0],a[1]);
		rep(i,a.size()) ans.pb(a[i]);
	}
	rep(i,ans.size()) cout<<ans[ans.size()-1-i]<<endl;
	return 0;
}