九度 1201

#include <cstdio>
#include <iostream>
using namespace std;

#ifdef ONLINE_JUDGE                                   
#define FINPUT(file)  0
#define FOUTPUT(file) 0
#else                                                
#define FINPUT(file)  freopen(file,"r",stdin)
#define FOUTPUT(file) freopen(file,"w",stdout)
#endif

struct binTree{
	int data;
	binTree *left;
	binTree *right;
};

void insertTree(binTree **root,binTree *node)
{
	if(*root==NULL)
	{
		*root = node;
		return ;
	}	

	if(node->data<(*root)->data)
		insertTree(&(*root)->left,node);
	else if(node->data>(*root)->data)
		insertTree(&(*root)->right,node);
	else if(node->data = (*root)->data)
		return;	
}

void preTvs(binTree *root)
{
	if(root)
	{
		cout<<root->data<<" ";
		preTvs(root->left);
		preTvs(root->right);
	}
}

void orTvs(binTree *root)
{
	if(root)
	{
		orTvs(root->left);
		cout<<root->data<<" ";
		orTvs(root->right);
	}
}

void postTvs(binTree *root)
{
	if(root)
	{
		postTvs(root->left);
		postTvs(root->right);
		cout<<root->data<<" ";
	}
}

int main()
{
    FINPUT("in.txt");
    FOUTPUT("out.txt");
    
    int n;
    while(cin>>n && n)
    {
    	binTree *bt = new binTree[n];
    	int i = 0;
    	binTree *root = NULL;
    	while(i<n)
    	{
    		int t;
    		cin>>t;
    		bt[i].data = t;
    		bt[i].right = bt[i].left = NULL;
    		insertTree(&root,&bt[i]);
    		i++;
    	}
    	/*    	*/
    	preTvs(root);
    	cout<<endl;
    	orTvs(root);
    	cout<<endl;
    	postTvs(root);
    	cout<<endl;

    }
    return 0;
}