#include<stdio.h>
#include<stdlib.h>
struct Node{
    int data;
    struct Node* left;
    struct Node* right;
};
struct Node* createNode(int value){
    struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
    newNode->data = value;
    newNode->left = NULL;
    newNode->right = NULL;
    return newNode;
}
struct Node* insert(struct Node*root,int value){
    if(root == NULL)
    return createNode(value);
    if(value<root->data)
    root->left = insert(root->left,value);
    else if(value>root->data)
    root->right = insert(root->right,value);
    return root;
}
void inOrderTraversal(struct Node* root){
    if(root!=NULL){
        inOrderTraversal(root->left);
        printf("%d",root->data);
        inOrderTraversal(root->right);
    }
}
int main(){
    int N,X;
    if(scanf("%d",&N)!=1)return 1;
    if(scanf("%d",&X)!=1)return 1;
    if(N<0 || X<0){
        printf("Invalid input\n");
        return 0;
    }
    struct Node* root = NULL;
    int val;
    for(int i =0;i<N;i++){
        if(scanf("%d",&val)!=1)
        return 1;
        if(val<0){
             printf("Invalid input\n");
             freeTree(root);
             return 0;
        }
        root = insert(root,val);
        }
        root = insert(root,X);
        inOrderTraversal(root);
        printf("\n");
        freeTree(root);
        return 0;
}