#include <iostream>
#include <string>
using namespace std;
#define MAXSIZE 100


class BiTree
{
private:
char data[MAXSIZE];//data[0]不用 
int n;
public:
BiTree();
void Insert(char x);
void PreOrder(int i);
void InOrder(int i);
void PostOrder(int i);
};
BiTree::BiTree()
{
n=0;
}


void BiTree::Insert(char x)
{
n++;
data[n]=x;
}
void BiTree::PreOrder(int i)
{
if(data[i]!='/')
{
cout<<data[i]<<" ";
if(2*i<=n&&data[2*i+1]!='/')
PreOrder(2*i);
if(2*i+1<=n&&data[2*i+1]!='/')
PreOrder(2*i+1);
}
}
void BiTree::InOrder(int i)
{
if(data[i]!='/')
{
if(2*i<=n&&data[2*i+1]!='/')
PreOrder(2*i);
cout<<data[i]<<" ";
if(2*i+1<=n&&data[2*i+1]!='/')
PreOrder(2*i+1);
}
}
void BiTree::PostOrder(int i)
{
PreOrder(2*i);
PreOrder(2*i+1);
if(data[i] != '/')
{
cout<<data[i]<<" ";
}
}
int main()
{
string str = "ABCDE/G//JK//NO";
//while(cin>>str)
//{
BiTree tree;
for(int i=0;i < str.length();i++)
{
tree.Insert(str[i]);
}
tree.PreOrder(1);
cout<<endl;
tree.InOrder(1);
cout<<endl;
tree.PostOrder(1);
cout<<endl; 
//}
return 0;
}