/**

* Initialize your data structure here.

*/

var MyQueue = function() {

this.front = [];

this.back = [];

};

/**

* Push element x to the back of queue.

* @param {number} x

* @return {void}

*/

MyQueue.prototype.push = function(x) {

this.front.push(x);

};

/**

* Removes the element from in front of queue and returns that element.

* @return {number}

*/

MyQueue.prototype.pop = function() {

if (!this.back.length) {

while (this.front.length) {

this.back.push(this.front.pop());

}

}

return this.back.pop();

};

/**

* Get the front element.

* @return {number}

*/

MyQueue.prototype.peek = function() {

if (!this.back.length) {

while (this.front.length) {

this.back.push(this.front.pop());

}

}

return this.back[this.back.length - 1];

};

/**

* Returns whether the queue is empty.

* @return {boolean}

*/

MyQueue.prototype.empty = function() {

return !this.front.length && !this.back.length;

};

/**

* Your MyQueue object will be instantiated and called as such:

* var obj = new MyQueue()

* obj.push(x)

* var param_2 = obj.pop()

* var param_3 = obj.peek()

* var param_4 = obj.empty()

*/