text: #include <cmath>
  #include <cstdio>
  #include <vector>
  #include <iostream>
  #include <algorithm>
  #include <cassert>
  using namespace std;
  
  template <typename T>
  class AddElements{
      public:
          T add(const T& e2);
      private:
          T element_;
  };
  
  template <typename T>
  T AddElements<T>::add(const T& e2) {
      return this->element_ + e2;
  }
  
  int main () {
      std::string e1 = "2";
      std::string resutls = "1" + e1;
    std::cout << resutls;
    return 0;
  }
  