// In the name of God
#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;

const int Mn=1000*1000+100;
int l[Mn], r[Mn], dad[Mn];

vector<int> ans_pish, ans_pas, ans_mian;

void print (vector<int> v){
	 for(int i=0; i<v.size(); i++)
	 		 cout<<v[i]<<" ";
	cout<<endl;	 
}

void pish_tartib(int x){
	if(x==0)
			return;
	ans_pish.push_back(x);
	pish_tartib(l[x]);
	pish_tartib(r[x]);
}

void pas_tartib(int x){
	 if(x==0)
	 		 return;
	 pas_tartib(l[x]);
	 pas_tartib(r[x]);
	 ans_pas.push_back(x);
}

void mian_tartib(int x){
	 if(x==0)
	 		 return;
	 mian_tartib(l[x]);
	 ans_mian.push_back(x);
	 mian_tartib(r[x]);
}

int main(){
	int n;
	cin>>n;
	int root=0;
	for(int i=1; i<=n; i++){
			int x;
			cin>>x;
			dad[i]=x;
			if(x==i)
					root=x;
			else if(l[x]==0)
	                l[x]=i;
			else r[x]=i;		
	}	
	
	pish_tartib(root);
	pas_tartib(root);
	mian_tartib(root);
	print(ans_pish);
	print(ans_pas);
	print(ans_mian);
	return 0;
}