#include<stdio.h>
#define size 1000
int queue[size];
int front=-1,rear=-1;
void display(){
    if(front==-1||front>rear){
        printf("%d\n");
    }
    else{
        for(int i=front;i<=rear;i++){
            printf("%d ",queue[i]);
        }
        printf("\n");
    }
}
int main(){
    display();
    return 0;
}