def common_isuffix(*strings):
"""Return the length of the common suffix of strings"""
i = -1
for i in xrange(0, min(len(s) for s in strings)):
if not eq(*(s[len(s) - i - 1] for s in strings)):
return i
return i + 1
def common_iprefix(*strings):
"""Return the length of the common prefix of strings"""
i = 0
for i in xrange(0, min(len(s) for s in strings)):
if not eq(*(s[i] for s in strings)):
return i
return i