sizeof my int = 8
0 + 1 = 1 (1)
1 + -1 = 0 (0)
69 + -42 = 27 (27)
42 + 69 = 111 (111)
-42 + 69 = 27 (27)
-42 + -69 = -111 (-111)
256 + 512 = 768 (768)
123456789 + 1 = 123456790 (123456790)
2147483647 + 1 = 2147483648 (2147483648)
-2147483648 + 1 = -2147483647 (-2147483647)