#include<iostream>
#include<queue>
using namespace std;

int main() {

	/* Create a queue */
	queue<int> data;

	/* Enqueue data into the queue */
	data.push(10);
	data.push(20);
	data.push(30);
	data.push(40);
	
	cout << "Queue size: " << data.size() << endl;
	cout << "Data on top of the queue: " << data.front() << endl;
	cout << "Data on bottom of the queue: " << data.back() << endl;

	/* Dequeue data from the queue */
	data.pop();

	cout << "Queue size after dequeue: " << data.size() << endl;
	cout << "Now top data on queue: " << data.front() << endl;
	cout << "Now bottom data on queue: " << data.back() << endl;
	
	return 0;
}


          /****** Output ******/
          
Queue size: 4

Data on top of the queue: 10

Data on bottom of the queue: 40

Queue size after dequeue: 3

Now top data on queue: 20

Now bottom data on queue: 40