#include <string>
#include <sstream>

inline std::string __FromHex(const std::string& in)
{
    if ((in.length() % 2) != 0) return "";
    std::string output;
    size_t cnt = in.length() / 2;
    for (size_t i = 0; cnt > i; ++i)
    {
        unsigned long int s = 0;
        std::stringstream ss;
        ss << std::hex << in.substr(i * 2, 2);
        ss >> s;
        output.push_back(static_cast<unsigned char>(s));
    }
    return output;
}

inline std::string __UltimateCipher(std::string Str)
{
    char Key[3] = { 'A', 'B', 'C' };
    std::string Encrypted = Str;
    for (unsigned int i = 0; i<Str.size(); i++) Encrypted[i] = Str[i] ^ Key[i % (sizeof(Key) / sizeof(char))];
    return Encrypted;
}

inline std::string __UltimateDecrypt(std::string MyString)
{
    return __UltimateCipher(__FromHex(MyString));
}

int main(void)
{
    //
    printf("%s\n", (__UltimateDecrypt("31233032352c33267e") + "hackshield" + __UltimateDecrypt("672f2632312226277e")).c_str());
    printf("%s\n", __UltimateDecrypt("707b706f75736f7a726f737675").c_str());
    printf("%s\n", __UltimateDecrypt("6e302622346d312a33").c_str());
}