new_contents: def btoi(a):
  	x = 0
  	for i in xrange(len(a)):
  		if a[i] == '1':
  			x += 2 ** i
  	return x
  
  def itob(a):
  	if a == 0:
  		return '0'
  	x = ''
  	while a > 0:
  		if a % 2 == 1:
  			x += '1'
  		else:
  			x += '0'
  		a /= 2
  	return x[::-1]
  
  def add(a,b):
  	x = btoi(a[::-1])
  	y = btoi(b[::-1])
  	z = x + y
  	return itob(z)
  
subject: Create addingBinary.py