Subtract in a string with decrementation

[GywfSL3A]

Hi,

First, here's my code :
>>>>>
std::vector<std::string> x = split("3 5", ' ');
int total = 0;
// then we loop over the elements
for(size_t i = 0; i < x.size(); ++i) {
// convert the string to an integer
int n = atoi(x[i].c_str());
total = total + n;
}

std::cout << "total = " << total << std::endl;
}
<<<<<

So, as you can see, this will add 3 to 5. However, I would like it to do the inverse (3 - 5).

How I can do that?
Thank you for your help.

[LB]

Will there always be two elements? What do you expect to happen with three or more elements in subtraction mode? Why does the first element get special treatment?

[Duthomhas]

It is not uncommon for (- 3 5 7) to mean (3 - 5 - 7), so there is no problem there.