void find_recursive(const wstring &pathIn, const wstring &ext, vector<wstring>& results) {
    static const wstring kThisDir=L".";
    static const wstring kParentDir=L"..";
    const wstring prefix = pathIn + L"\\";
    const wstring allFiles = prefix + L"*.*";


    WIN32_FIND_DATA findData;
    HANDLE hFind = FindFirstFile(allFiles.c_str(), &findData);
    if(hFind == INVALID_HANDLE_VALUE) throw std::runtime_error("Error searching in directory");

    while(FindNextFile(hFind , &findData) != 0) {
        if(findData.cFileName == kThisDir || findData.cFileName == kParentDir) {
            continue;
        }
        if(FILE_ATTRIBUTE_DIRECTORY & findData.dwFileAttributes){
            get_path_pdn(prefix + findData.cFileName, results);
        }
        else {
            wstring foundFile = findData.cFileName;
            if(foundFile.substr(foundFile.length() - ext.length()) == ext) {
                results.push_back(prefix + foundFile)
            }
        }
    }


    DWORD dwError = GetLastError();
    if (dwError != ERROR_NO_MORE_FILES) {
        wstring Error;
        Error += L"FindNextFile error. Error is ";
        Error += dwError;
        wcout << Error;
    }
    FindClose(hFind);
}

vector<wstring> get_path_pdn(const wstring &pathIn) {
    std::vector<wstring> result;
    find_recursive(pathIn, L".pdn", result)
    return result;
}