Concise C++
\nclass Solution {\npublic:\n    long long maxMatrixSum(vector<vector<int>>& matrix) {\n        long long mn = INT_MAX, cnt = 0, sum = 0;\n        for(auto r : 
```\nclass Solution {\npublic:\n    long long maxMatrixSum(vector<vector<int>>& matrix) {\n        long long mn = INT_MAX, cnt = 0, sum = 0;\n        for(auto r : matrix) {\n            for(int i : r) {\n                if(i < 0) cnt++;\n                mn = min(mn, (long long)abs(i));\n                sum += abs(i);\n            }\n        }\n        return cnt % 2 ? sum - 2 * mn : sum;\n    }\n};\n```
['C++']