function Stack() {

	var items = [];

	this.push = function(item) {

		items.push(item)

	}

	this.pop = function() {

		return items.pop()

	}

	this.peek = function() {

		return items[items.length - 1]

	}

	this.isEmpty = function() {

		return items.length == 0

	}

	this.size = function() {

		return items.length

	}

	this.clear = function() {

		items = []

	}

	this.printf = function() {

		console.log(items.toString())

	}

	this.divideBy2 = function(decNumber) {

		var remStack = new Stack(),

		rem,

		binaryString = '';

		while (decNumber > 0) {

			rem = Math.floor(decNumber % 2);

			remStack.push(rem);

			decNumber = Math.floor(decNumber / 2)

		}

		while (!remStack.isEmpty()) {

			binaryString += remStack.pop().toString()

		}

		return binaryString

	}

}

var stacks = new Stack();

console.log(stacks.isEmpty());

stacks.push(5);

stacks.push(4);

console.log(stacks.peek());

stacks.push(11);

console.log(stacks.size());

console.log(stacks.isEmpty());

stacks.push(15);

stacks.pop();

console.log(stacks.size());

stacks.printf();

console.log(stacks.divideBy2(33));