>>> x
[(12, 12), (13, 15), (67, 25), (69, 19), (74, 74), (54, 54), (99, 99), (49, 49), (13, 20), (92, 40), (12, 50), (96, 30), (35, 15), (12, 20), (78, 28), (44, 30)]
>>> len(x)
16
>>> sorted(x)
[(12, 12), (12, 20), (12, 50), (13, 15), (13, 20), (35, 15), (44, 30), (49, 49), (54, 54), (67, 25), (69, 19), (74, 74), (78, 28), (92, 40), (96, 30), (99, 99)]
>>> xs = sorted(x)
>>> len(xs)
16
>>> smallxs = xs[:8]
>>> len(smallxs)
8
>>> largexs = xs[8:]
>>> len(largexs)
8
>>> sum = 0
>>> for a,b in smallxs:
...   sum += b
... 
>>> sum
211
>>> sum = 0
>>> for a,b in largexs:
...  sum += b
... 
>>> sum
369
>>>