The idea of designing and developing an adder of integers is due to the fact that integer numbers have always limits on their minimum and maximum values. To overcome this shortcoming, integers are treated as sequences of numeric characters. We would like to implement an adder of two integers. This adder should take into consideration that the two input integer numbers are entered in the form of finite sequences of numeric characters, namely 0, , 9. Write a C++ program that accepts two integers (each of them could be positive, negative, or zero) as input and generates as output the result of their addition. Both integers are entered by the 2 user and saved into two string variables, named S_ENT1 and S_ENT2, respectively. Similarly, the result of their addition should be saved into a third string variable, S_ENT3. An integer is a sequence of characters including only digits, namely 0, , 9. Thus, both integers should be checked so that no other character could be entered. The implementation of this adder should be as structured as possible.