Fwnies' solution to NCPC 2013 problem E

E.py

xs = raw_input()
ys = raw_input()
 
lxs = len(xs)
lys = len(ys)
d = lys - lxs
 
i = 0
while True:
    if i >= min(lxs, lys):
        break
    if xs[i] <> ys[i]:
        break
    i += 1
 
j = i + max(0, d)
while True:
    if j >= lys:
        break

    if ys[j:] == xs[j - d:]:
        break
    j += 1
 
print j - i