LISP-like expression list execution

/******************************************************************************************
*******************************************************************************************
** Write a program that takes an operation followed by two operands and outputs the result. For
** example:
** + 100 3.14
** * 4 5
**
*/

#include "../../std_lib_facilities.h"

int main()
{
    cout << "Pass an operator followed by its operands and execute the expression ( (+ 1 1) => 2 ):\n";
    char ops = ' ';
    int n1 = 0, n2 = 0;
    double res;
    cin >> ops;
    cin >> n1 >> n2;

    cout << "The result of (" << ops << " " << n1 << " " << n2 << ") is: \n";

    if (ops == '+') {
        res = n1 + n2;
    } else if (ops == '-') {
        res = n1 - n2;
    } else if (ops == '*') {
        res = n1 * n2;
    } else if (ops == '/') {
        res = n1 * n2;
    } else if (ops == '%') {
        res = n1 % n2;
    }

    cout << res << "\n";

    return 0;
}