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import fileinput
with fileinput.input() as lines:
a = [tuple(int(x) for x in l[:-1].split(',')) for l in lines]
# Check if the border is turning clockwise or counter-clockwise
def dir(p, q):
return p[0]*q[1]-p[1]*q[0]
t = 0
for i in range(len(a)):
p, q, r = a[i%len(a)], a[(i+1)%len(a)], a[(i+2)%len(a)]
t += 1 if dir((q[0]-p[0],q[1]-p[1]), (r[0]-q[0],r[1]-q[1])) > 0 else -1
def external_by_vertex(a, i, j):
p = tuple(a[(i+1)%len(a)][k] - a[i][k] for k in range(2))
q = tuple(a[j][k] - a[i][k] for k in range(2))
return t * dir(p, q) < 0
def lbreaks(p, q, tl, br):
# Adjust for horizontal or vertical
(tt, z) = (t, 0) if p[0] == q[0] else (-t, 1)
if min(p[1-z], q[1-z]) >= br[1-z] or max(p[1-z], q[1-z]) <= tl[1-z]:
return False
if p[z] == tl[z]:
return tt * (q[1-z]-p[1-z]) > 0
if p[z] == br[z]:
return tt * (q[1-z]-p[1-z]) < 0
return p[z] > tl[z] and p[z] < br[z]
def admissible(a, i, j):
# Fix (see ../README.md): check given vertices to determine if the
# rectangle is fully external to the figure.
if external_by_vertex(a, i, j):
return False
tl = (min(a[i][0], a[j][0]), min(a[i][1], a[j][1]))
br = (max(a[i][0], a[j][0]), max(a[i][1], a[j][1]))
return not any(lbreaks(a[k], a[(k+1)%len(a)], tl, br) for k in range(len(a)))
s = 0
for i in range(len(a)):
for j in range(i+1, len(a)):
if admissible(a, i, j):
s = max(s, (abs(a[i][0]-a[j][0])+1)*(abs(a[i][1]-a[j][1])+1))
print(s)
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