func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t, m, n, z, s, q, p;     cin >> t;     while (t--) {       cin >> n >> m;       int a[n][m], z = 200, s = 0, p = 0;       for (int i = 0; i < n; ++i) {         for (int j = 0; j < m; ++j) {           cin >> a[i][j];           if (a[i][j] < 0) {             ++p;           }           z = min(z, abs(a[i][j]));           s = s + abs(a[i][j]);         }       }       if (p % 2 == 1) {         s = s - 2 * z;         cout << s << endl;       } else         cout << s << endl;     }   }   