func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.precision(10);     cout << fixed;     int n, neg = 0;     cin >> n;     vector<int> a(2 * n - 1);     bool zero = false;     long long sum = 0;     for (int i = 0; i < 2 * n - 1; ++i) {       cin >> a[i];       if (a[i] == 0)         zero = true;       else if (a[i] < 0)         neg++, a[i] *= -1;       sum += a[i];     }     neg %= n;     if (zero) neg = 0;     vector<bool> vis(2 * n);     queue<int> q;     q.push(neg);     vis[neg] = 1;     int ans = neg;     while (!q.empty()) {       int k = q.front();       q.pop();       if (k % n == 0) {         ans = 0;         break;       }       ans = min(ans, k);       for (int x = 2 * n - 1 - k; x >= n - k; --x) {         int k2 = k + 2 * x - n;         if (k2 > 0 && k2 < 2 * n && !vis[k2]) {           vis[k2] = 1;           q.push(k2);         }       }     }     sort(begin(a), end(a));     for (int i = 0; i < ans; ++i) sum -= 2 * a[i];     cout << sum <<   n ;     return 0;   }   