#include <vector>
#include <unordered_map>
#include <numeric>

int unique_sum(const std::vector<int>& n)
{
  std::unordered_map<int,int> frequencies;
  for (auto i : n) 
      ++frequencies[i]; 
  
  return std::accumulate(begin(n), end(n), 0, [&](auto sum, auto i){
    return frequencies[i] == 1 ? sum + i : sum;
  });
}

#include <bits/stdc++.h>
using namespace std;
int unique_sum(vector<int> nums) {
  sort(nums.begin(), nums.end());
  int sum = 0;
  for(size_t i = 0; i < nums.size(); i++) {
    if(nums[i] == nums[i+1] || nums[i] == nums[i-1]) {
      continue;
    } else {
      sum += nums[i];
    }
  }
  return sum;
}