import java.security.cert.TrustAnchor;
import java.util.*;

class Cir_Queue {
    private int[] data;
    private int front, rear, size;

    Cir_Queue(int size){
        this.data = new int[size];
        this.front = -1;
        this.rear = -1;
        this.size = size;
    }

    public boolean isEmpty(){
        return this.front == -1;
    }

    public boolean isFull(){
        return (this.rear + 1)%(this.size) == front;
    }

    public void enqueue(int value){
        if(this.isFull()){
            System.out.println("Queue is Full!");
            return;
        }
        if(this.isEmpty()){
            this.front = 0;
        }
        this.rear = (this.rear + 1)%(this.size);
        this.data[rear] = value;
    }

    public int dequeue(){
        if(this.isEmpty()){
            System.out.println("Queue is Empty!");
            return -1;
        }
        int value = this.data[this.front];
        if(this.rear == this.front){
            this.rear = -1;
            this.front = -1;
        }
        else {
            this.front = (this.front + 1)%this.size;
        }

        return value;
    }

    public int peek(){
        if(this.isEmpty()){
            System.out.println("Queue is Empty!");
            return -1;
        }
        return this.data[this.front];
    }

    public void info(){
        if(this.isEmpty()){
            System.out.println("큐가 비어있습니다.");
            return;
        }

        StringBuilder result = new StringBuilder("Queue List : ");
        int i = this.front;
        while(true){
            result.append(this.data[i] + " ");
            if(i==this.rear) break;
            i = (i + 1)%this.size;
        }
        System.out.println(result);
    }
}

public class DS_queue {
    public static void main(String[] args) {
        Scanner sc= new Scanner(System.in);
        System.out.println("큐의 사이즈를 입력해주세요.");
        int size = Integer.parseInt(sc.nextLine());
        Cir_Queue q = new Cir_Queue(size);

        boolean exitFlag = true;
        while(exitFlag){
            System.out.println("명령어 목록 : enque [value] | deque | peek | info | exit");
            String[] opcode = sc.nextLine().split(" ");
            switch (opcode[0]) {
                case "enque":
                    q.enqueue(Integer.parseInt(opcode[1]));
                    break;
                case "deque":
                    if(q.isEmpty()){
                        q.dequeue();
                        break;
                    }
                    System.out.println(q.dequeue());
                    break;
                case "peek":
                    if(q.isEmpty()){
                        q.peek();
                        break;
                    }
                    System.out.println(q.peek());
                    break;
                case "info":
                    q.info();
                    break;
                case "exit":
                    exitFlag = false;
                    System.out.println("Exit!!");
                    break;
                default:
                    System.out.println("제대로 입력해주세요.");
                    break;
            }
        }
        sc.close();
    }
}