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