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