a = 00 b = 00 a = 01 b = ffffffff00000001000000000000000000000000fffffffffffffffffffffffe a = 02 b = ffffffff00000001000000000000000000000000fffffffffffffffffffffffd a = 03 b = ffffffff00000001000000000000000000000000fffffffffffffffffffffffc a = ffffffff00000001000000000000000000000000fffffffffffffffffffffffe b = 01 a = 7fffffff800000008000000000000000000000007fffffffffffffffffffffff b = 7fffffff80000000800000000000000000000000800000000000000000000000 a = 7fffffff80000000800000000000000000000000800000000000000000000000 b = 7fffffff800000008000000000000000000000007fffffffffffffffffffffff a = 8000000000000000000000000000000000000000000000000000000000000000 b = 7fffffff00000001000000000000000000000000ffffffffffffffffffffffff