text: #include <iostream>
  #include <vector>
  
  auto concatenateVector(std::vector<int>& first_vector, std::vector<int>& second_vector){
      std::vector<int> result_vector;
      for (size_t i = 0; i < first_vector.size() || i < second_vector.size(); i++){
          if (i < first_vector.size()){
              result_vector.push_back((first_vector[i]));
          }
          if (i < second_vector.size()){
              result_vector.push_back((second_vector[i]));
          }
      }
      return result_vector;
  }
  
  int main() {
      std::vector<int> vec1 {1, 2, 3, 4};
      std::vector<int> vec2 {11};
  
      auto vec = concatenateVector(vec1, vec2);
      for (const auto& el : vec) {
          std::cout << el << " ";
      }
      return 0;
  }
  