#include<stdio.h>
#include<string.h>
#define MAX 100
int deque[MAX];
int front=MAX/2,rear=MAX/2-1;
void join_front(int x){
    if(front==0){
        return;
    }
        front--;
        deque[front]=x;
    }
void join_rear(int x){
    if(rear==MAX-1){
        return;
    }
    rear++;
    deque[rear]=x;
}
void issue()
{
    if(front>rear)return;
    {
        printf("\n");
        front++;
    }
}
void display(){
    if(front>rear){
        printf(" ");
        return;
    }
    for(int i=front;i<=rear;i++){
        printf("%d",deque[i]);
        if(i<rear)printf(" ");
    }
printf(" ");
}
int main(){
    int n,x;
    char cmd[20];
    scanf("%d",&n);
    for(int i=0;i<n;i++){
        scanf("%s",cmd);
    }
}'
}