Number in string atoi

# include <iostream>
using namespace std;
#include <iomanip>
#include <math.h>
#include <cmath>
#include <string>
int main()
{
    string temp;
    cin >> temp;
    int sum = 0;
    do {
        int num = atoi(temp.c_str());
        sum += num;
        cin >> temp;
    } while (temp != "Stop");
    cout << sum << endl;

    return 0;
}