# include  
using namespace std; 
Typedef struct TreeNode * Tree; 
Struct TreeNode {
Int Element; 
Tree Left; 
The Tree Right; 
}; 
Struct Stack {
The Tree Node. 
Stack * Next; 
}; 
Void Push (Tree, Stack *); 
Void CreatNew (int, Tree, Stack *); 
Tree, the Tree CreatNULL (Stack *); 
Tree Pop (Stack *); 
Void PostOrderTraversal (Tree); 
Int main () {
Int node_number, node_index; 
Char operation [4]. 
Stack * S=new Stack; 
S -> Next=NULL; 
The Tree root. 
The root=new TreeNode. 
Cin> node_number; 
Cin> operation. 
Cin> node_index; 
Tree new_node=new TreeNode. 
Root -> Left=new_node; 
The root Element ->=node_index; 
Push (root, S); 
Tree temp=new_node; 
for (int i=1; I <2 * node_number; I++) {
Cin> operation. 
if (! STRCMP (operation, "Push")) {
Cin> node_index; 
CreatNew (node_index, temp, S); 
} 
The else 
Temp=CreatNULL (temp, S); 
} 
Temp=NULL; 
PostOrderTraversal (root); 
return 0; 
} 
Void CreatNew (int x, Tree T, Stack * S) {
Tree new_node=new TreeNode. 
T -> Left=new_node; 
T -> Element=x; 
Push (T, S); 
T=T -> Left; 
} 
Void Push (Tree T, Stack * S) {
Stack * temp=new Stack; 
Temp -> Next=S -> Next; 
S -> Next=temp; 
Temp -> Node=T; 
} 
Tree CreatNULL (Tree T, Stack * S) {
T=NULL; 
Tree poped; 
Poped=Pop (S); 
Tree anewnode=new TreeNode. 
Anewnode=poped -> Right; 
Return anewnode; 
} 
Tree Pop (Stack * S) {
Stack * temp; 
Tree tempTree; 
Temp=S -> Next; 
S -> Next=temp -> Next; 
TempTree=temp -> Node. 
Delete (temp); 
Return tempTree; 
} 
Void PostOrderTraversal (Tree T) {
If (T) {
PostOrderTraversal (T -> Left); 
PostOrderTraversal (T -> Right); 
Cout  Element <""; 
} 
}