#include<stdio.h>
#include<stdlib.>

typedef struct node{
    int data;
    node *next;
}node;
node *head=NULL,*tail;

void create(int num){
    node *newnode=(node*)malloc(1*sizeof(node));
    newnode->data=num;
    newnode->next=NULL;
    if(head==NULL){
        head=newnode;
        tail=newnode;
    }
    else{
        tail->next=newnode;
        tail=newnode;
    }
}

void display(int mid){
    node *i;
    for(i=head;i!=mid;i=i->next){
        printf("%d",i->mid)
    }
}

int main(){
    int s,n,i;
    float mid;
    scanf("%d",&s);
    if(s<0){
        printf("Invalid input");
        return 0;
    }
    for(i=0;i<s;i++){
        if(!scanf("%d",&n)){
            printf("Invalid input");
            return 0;
        }
    }
    mid=s/2;
    display(mid);
    return 0;
}