func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     vector<int> a(n + n - 1);     int sum = 0;     for (int i = 0; i < n + n - 1; i++) {       cin >> a[i];       sum += a[i];     }     sort(a.begin(), a.end());     for (int i = 0; i < n + n - 2; i += 2) {       if (a[i] < 0 && a[i + 1] < 0) {         sum -= a[i] + a[i];         sum -= a[i + 1] + a[i + 1];         a[i] = -a[i];         a[i + 1] = -a[i + 1];       } else if (a[i] < 0) {         if (-a[i] > a[i + 1]) {           sum -= a[i] + a[i];           sum -= a[i + 1] + a[i + 1];           a[i] = -a[i];           a[i + 1] = -a[i + 1];         }       } else {         break;       }     }     if (n % 2) {       sort(a.begin(), a.end());       if (a[0] < 0) {         sum -= a[0] + a[0];       }     }     cout << sum << endl;     return 0;   }   