int  add_sum(vector<int>&nums,int i)
{
  int sum=nums[0];
  if(i==nums.size()-1)
    return 0;
  for(int j=i+1;j<nums.size();j++)
  { 
    sum+=nums[j];
    add_sum(nums,j);
  }
  return sum;
}

int main()
{
  vector<int >vec;
  vec.push_back(1);
  vec.push_back(5);
  vec.push_back(4);
  cout<<add_sum(vec,0);

  return 0;
}