func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     vector<int> a;     int cnt = 0;     int sum = 0;     for (int i = 0; i < 2 * n - 1; ++i) {       int x;       cin >> x;       a.push_back(abs(x));       if (x < 0) cnt++;       sum += abs(x);     }     cnt %= n;     queue<int> q;     vector<bool> used(n + 1, false);     used[cnt] = 1;     q.push(cnt);     int c = cnt;     while (!q.empty()) {       int u = q.front();       q.pop();       if (!used[n - u]) {         used[n - u] = 1;         q.push(n - u);         c = min(c, n - u);       }       for (int i = 1; i <= u; ++i) {         int to = u - i + n - i;         to %= n;         if (to >= 0 && !used[to]) {           used[to] = 1;           q.push(to);           c = min(c, to);         }       }     }     sort(a.begin(), a.end());     if (c == 0) {       cout << sum;     } else {       for (int i = 0; i < c; ++i) {         sum -= 2 * a[i];       }       cout << sum;     }     return 0;   }   