#include<stdio.h>
#include<stdlib.h>
typedef struct tree{
    int data;
    struct tree* left,*right;
}node;
node* root=NULL;
node* create(int num){
    node* newnode=(node*)malloc(sizeof(node));
    newnode->data=num;
    newnode->left=NULL;
    newnode->right=NULL;
    return newnode;
}
node* insert(node* root,int num){
    if(root==NULL)
        return create(num);
    if(num<root->data)
        root->left=insert(root->left,num);
    else
        root->right=insert(root->right,num);
    return root;
}
void inorder(node* root){
    if(root!=NULL){
        inorder(root->left);
        printf("%d\n",root->data);
        inorder(root->right);
    }
   
}
void preorder(node* root){
    if(root!=NULL){
        printf("%d\n",root->data);
        preorder(root->left);
        preorder(root->right);
    }
     printf('\n');
}
void postorder(node* root){
    if(root!=NULL){
        
        postorder(root->left);
        postorder(root->right);
        printf("%d\n",root->data);
    }
     printf('\n');
}
int main(){
    int size,num,i;
    scanf("%d",&size);
    if(size<0){
        printf("Invalid input");
        return 0;
    }
    for(i=0;i<size;i++){
        scanf("%d",&num);
        root=insert(root,num);
    }
    inorder(root);
    preorder(root);
    postorder(root);
    return 0;
}