#include<bits/stdc++.h>
using namespace std;

const int MAX = 10;

class MyQueue {
    int L, R;
    int a[MAX];

    public:
        MyQueue();
        void push(int num);
        void pop();
        int front();
        int rear();
        int size();
        bool is_empty();
};

MyQueue::MyQueue() {
    L = R = -1;
}

void MyQueue::push(int num) {
    if(R >= MAX - 1) {
        cout << "Queue overflow!\n";
        return;
    }

    a[++R] = num;

    if(L == -1) L = R;
}

void MyQueue::pop() {
    if(L == -1) {
        cout << "Queue empty!\n";
        return;
    }

    L += 1;

    if(L > R) {
        L = -1;
        R = -1;
    }
}

int MyQueue::front() {
    if(L == -1) {
        cout << "Queue empty!\n";
        return INT_MAX;
    }

    return a[L];
}

int MyQueue::rear() {
    if(R == -1) {
        cout << "Queue empty!\n";
    }

    return a[R];
}

int MyQueue::size() {
    if(L == -1) return 0;
    else return (R - L + 1);
}

bool MyQueue::is_empty() {
    if(L == -1) return 1;

    int siz = R - L + 1;
    return siz == 0;
}

void solve()
{
    MyQueue q;
    q.push(10);
    q.push(20);
    q.push(30);
    q.push(49);
    q.push(-107);
    q.push(13);

    cout << q.front() << " is the front element of queue\n";
    cout << q.rear() << " is the rear element of queue\n";

    q.pop();
    cout << "Size of queue: " << q.size() << "\n";

    // print all elements in stack :
    cout << "Elements present in queue: ";

    while(!q.is_empty()) {
        // print top element in stack
        cout << q.front() << " ";
        // remove top element in stack
        q.pop();
    }
}

int main()
{
    ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
    srand(chrono::high_resolution_clock::now().time_since_epoch().count());

    // #ifndef ONLINE_JUDGE
    //     freopen("input.txt", "r", stdin);
    //     freopen("output.txt", "w", stdout);
    // #endif

    // #ifndef ONLINE_JUDGE
    //      freopen("error.txt", "w", stderr);
    // #endif

    int t = 1;
    // int test = 1;
    // cin >> t;
    while(t--) {
        // cout << "Case #" << test++ << ": ";
        solve();
    }

    return 0;
}