include <iostream>
  include <numeric>
  include <vector>
  include <cmath>
  include <functional>
  using namespace std;
  
  double geometricMean(const vector<int>& nums)
  {
    double mult = accumulate(nums.begin(), nums.end(), 1,
                             multiplies<int>());
    return (pow(mult, 1.0 / nums.size()));
  }
  
  int main(int argc, char** argv)
  {
    plus<int> myPlus;
  
    int res = myPlus(4, 5);
    cout << res << endl;
  
    vector<int> myVector;
  
    int num;
    while (true) {
      cout << "Enter a test score to add (0 to stop): ";
      cin >> num;
      if (num == 0) {
        break;
      }
      myVector.push_back(num);
    }
  
    cout << "The geometric mean is " << geometricMean(myVector) << endl;
  
    return (0);
  }