C++ :: How To Make Cin Accept Different Punctuation From Vector

My program is a dictionary vector with a cin at the end that will read your input and check if it's in the dictionary.

#include "std_lib_facilities_3.h"
#include <algorithm>
#include <string>
#include <iostream>

string translate_to_lower(string s){
transform(s.begi[/code]n(), s[/code].end(), s.begin(), (int (*)(int)) tolower);

[Code] ...

How do I make the program accept inputs such as "hello?", "hello!", and "hello,"?