C++ please!!

You are given a string of any length. Return a new string consisting of the first and last characters concatenated together. You cannot use the at() member function or the subscript operator []. If the is less than length 2, return the original string. main.cpp \#include using namespace std; / Returns a string consisting of the first and last characters. aparam s the string to processes areturn the first and last characters concatenated together. string firstlast (const string\& s) \{ // Write your function here \}