#include<stdio.h>
#include<stdlib.h>
#include<ctype.h>
#include<string.h>
stuct Node{
    int data;
    struct Node*prev;
    struct Node*next;
};
struct Node*createNode(int data){
    struct Node*newNode=(struct Node*)malloc(sizeof(struct Node));
    newNode->data=data;
    newNode->prev=NULL;
    newNode->next=NULL;
    return newNode;
}
void append(struct Node**head,int data){
    struct Node*newNode=createNode(data);
    if(*head==NULL){
        *head=newNode;
        return;
    }
    struct Node*temp=*head;
    while(temp->next!=NULL){
        temp=temp->next;
    }
    temp->next=newNode;
    newNode->prev=temp;
}
void sortList(struct Node*head){
    struct Node*i;
    struct Node*j;
    int temp;
    for(i=head;i!=NULL;i=i->next){
        for(j=i->next;j!=NULL;j=j->next){
            if(j=i->next;j!=NULL;j=j->next){
                if(i->data>j->data){
                    temp=i->data;
                    i->data=j->data;
                    j->data=temp;
                }
            }
        }
    }
void printList(struct Node*head){
    struct Node*temp=head;
    while(temp!=NULL){
        printf("%d",temp->data);
        temp=temp->next;
    }
    printf("\n");
}
int main(){
    int n;
    if(scanf("%d",&n)!=1||n<1||n>1000){
        printf("Invalid input\n");
        return 0;
    }
    struct Node*head=NULL;
    for(int i=0;i<n;i++){
        char buffer[50];
        if(scanf("%s",buffer)!=1){
            printf("Invalid input\n");
            return 0;
        }
        for(int k=0;k<strlen(buffer);k++){
            if(!isdigit(buffer[k])&&!(k==0 && buffer[k]=='-')){
                printf("Invalid input\n");
                return 0;
            }
        }
        int value=atoi(buffer);
        append(&head,value);
    }
    sortList(head);
    printList(head);
    return 0;
}
}