Write a c++ program to calculate addition of two very large positive integers. The size of input integer is larger than C++ can handle, e.g. more than 30 digits. Therefore you may need consider user input as string. You may assume that the first input is not less than the second input, and all integers involved (including answer) are less than 1000 digits.

Hint: Don’t miss the fact that answer may have more or less digits than user input. e.g. 999 + 999 = 1998 (not 998), and 999 - 999 = 0 (not 000).