text: #include <iostream>
  #include <vector>
  
  int main()
  {
    std::vector<char> v;
  
    char c;
    while(std::cin.get(c))
      v.push_back(c);
  
    if (!v.empty())
      for(auto i = v.rbegin(); i <= v.rend(); ++i)
        std::cout << *i;
  }
  