from hex to 1 dec
'a:2:35:af:1' -> 10 + 2 + 53 + 175 + 1 -> 241
'b:356:3af:cba24:100' -> 11 + 854 + 943 + 834084 + 256 -> 836148
decr = lambda a: sum([int(h,16) for h in a.split(':')])
test.assert_equals(decr('a:2:35:af:1'),241)
test.assert_equals(decr('b:356:3af:cba24:100'),836148)
test.assert_equals(decr('a:bbbcefff:134fdea:100'),3169971955)
test.assert_equals(decr('effbc4:edfc31:aedfc2506'),46973721851)
test.assert_equals(decr('ef23fae:123a'),250761704)