#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int n1;
  n1 = 2 * n - 1;
  int a[n1];
  int sum = 0, i;
  bool b = true;
  for (i = 1; i <= n1; i++) {
    cin >> a[i];
    sum += a[i];
    if (a[i] < 0) b = false;
  }
  if (b) {
    cout << sum << endl;
  } else {
    int max = sum;
    int mini;
    int j;
    for (int i1 = 1; i1 <= n1; i1++) {
      for (i = 1; i <= n; i++) {
        mini = 1;
        for (j = 2; j <= n1; j++) {
          if (a[j] < a[mini]) mini = j;
        }
        sum -= a[mini];
        a[mini] *= -1;
        sum += a[mini];
      }
      if (max < sum) max = sum;
    }
    cout << max << endl;
  }
  return 0;
}
