text: #include <algorithm>
  #include <cassert>
  #include <cstdint>
  #include <fstream>
  #include <iostream>
  #include <iterator>
  
  int main(const int argc, const char* const argv[])
  {
    // Getting away with no error checking throughout because CodeEval makes some
    // strong guarantees about our runtime environment. No need to pay when we're
    // being benchmarked. Don't forget to define NDEBUG prior to submitting!
    assert(argc >= 2 && "Expecting at least one command-line argument.");
  
    std::ifstream inputStream(argv[1]);
  
    assert(inputStream && "Failed to open input stream.");
  
    using input_iterator  = std::istream_iterator<std::int_fast32_t>;
    using output_iterator = std::ostream_iterator<const char*>;
  
    std::transform(input_iterator(inputStream),
                   input_iterator(),
                   output_iterator(std::cout, "\n"),
                   [](const input_iterator::value_type age)
    {
      if(age < 0 || age > 100) return "This program is for humans";
  
      return age <=  2 ? "Still in Mama's arms" :
             age <=  4 ? "Preschool Maniac"     :
             age <= 11 ? "Elementary school"    :
             age <= 14 ? "Middle school"        :
             age <= 18 ? "High school"          :
             age <= 22 ? "College"              :
             age <= 65 ? "Working for the man"  :
                         "The Golden Years";
    });
  }
  