Letters

#include <iostream>
#include <string>
#include <sstream>
#include <memory>
#include <algorithm>
#include <cctype>
#include <vector>
#include<set>
#include <ctype.h>

using namespace std;


int main()
{
    vector<string> allWords;

    string line;
    getline(cin, line);

    for (char& c : line)
        if (!(c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z'))
            c = ' ';

    istringstream istr(line);
    string curEl;



    while (istr >> curEl)
    {
        allWords.push_back(curEl);
    }

    char letter;
    cin >> letter;
    cin.ignore();

    while (letter != '.')
    {
        set<string> forPrint;


        for (size_t i = 0; i < allWords.size(); i++)
        {
            string originalWord = allWords[i];
            string testCopy = originalWord;

            string* upperWord = &testCopy;


            transform(upperWord->begin(), upperWord->end(), upperWord->begin(), ::toupper);


            char upperSym = toupper(letter);

            size_t found = testCopy.find_first_of(upperSym);

            if (found != std::string::npos)
            {
                forPrint.insert(originalWord);
            }

        }

        if (forPrint.empty())
        {
            cout << "---" << endl;

        }
        else
        {
            set<string>::iterator itr;

            for (itr = forPrint.begin(); itr != forPrint.end(); itr++)
            {
                cout << *itr << " ";
            }

            cout << endl;

        }


        cin >> letter;
        cin.ignore();
    }


    cout << endl;

    return 0;
}