class Solution {
private:
 int sigh(vector <int> &arr , int idx)
    {
         int sz = arr.size();
        while ((idx < sz) && (arr[idx] == 0))
        {
            idx++;
        }

        int res = INT_MAX;

        for (int i = idx + 1; i < sz; i++)
        {
            if ((arr[idx] ^ arr[i]) < 0)
            {
                arr[i] += arr[idx];
                res = min(res, sigh(arr, idx + 1) + 1);
                arr[i] -= arr[idx];
            }
        }

        return (res == INT_MAX) ? 0 : res;
    }

public:
    int minTransfers(vector<vector<int>>& transactions) {
        unordered_map<int, int> all;

        for (const vector<int> &x : transactions) {
            all[x[0]] -= x[2];
            all[x[1]] += x[2];
        }

        unordered_multiset<int> fin;
        int same = 0;
        for (const pair<int, int> &x: all)
        {

            if (x.second != 0)
            {
                auto it = fin.find(-x.second);
                if (it != fin.end())
                {
                    fin.erase(it);
                    same++;
                }
                else
                {
                    fin.insert(x.second);
                }
            }
        }

        vector<int> arr (fin.begin(), fin.end());
        return same + sigh (arr, 0);
    }
};