```
class Solution:
def computeArea(self, a, b, c, d, e, f, g, h):
width = self._compute(a, c, e, g)
height = self._compute(b, d, f, h)
return (c - a) * (d - b) + (g - e) * (h - f) - width * height
def _compute(self, a, b, c, d):
if a > c:
a, b, c, d = c, d, a, b
if c < b < d:
return b - c
if d <= b:
return d - c
return 0
```