func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAX_N = 545;   int a[MAX_N];   int main() {     int n, minus = 0;     cin >> n;     int sum = 0;     for (int i = (0); i < (int)(2 * n - 1); ++i) {       cin >> a[i];       if (a[i] < 0) {         a[i] = abs(a[i]);         minus++;       }       sum += a[i];     }     sort(a, a + (2 * n) - 1);     if (n % 2 == 0 && minus % 2) sum -= (a[0] * 2);     cout << sum << endl;     return 0;   }   