plus

if (input == '3')
            {
                cout << "Total salary for a given year and a given SSN" << endl;
                string sendInSSN;
                cout << "Input SSN: ";
                cin >> sendInSSN;
                vector<Employee> temp = employee_sevice.testing(sendInSSN);
                double sum = 0;

                for (int i = 0; i < temp.size(); i++)
                {
                    sum+= temp[i].get_salary();
                }
                cout << sum << endl;

                if (temp.size() == 0){
                cout << "No employee with that SSN, unfortunately " << endl;
                }