0 0 -> 0 0
-1 ffffffff -> 1 1
1 1 -> 2 2
-63 ffffffc1 -> 125 7d
-64 ffffffc0 -> 127 7f
63 3f -> 126 7e
64 40 -> 128 80
-2147483647 80000001 -> 4294967293 fffffffd
-2147483648 80000000 -> 4294967295 ffffffff
2147483646 7ffffffe -> 4294967292 fffffffc
2147483647 7fffffff -> 4294967294 fffffffe