#include <bits/stdc++.h>
using namespace std;
const int MAXN = 200;
int n, arr[MAXN];
int main() {
  cin >> n;
  int numNegative = 0, sum = 0, sub = (1 << 30);
  for (int(i) = 0, _i = (2 * n - 1); (i) < _i; i++) {
    cin >> arr[i];
    sum += abs(arr[i]);
    sub = abs(arr[i]) > sub ? sub : abs(arr[i]);
    if (arr[i] < 0) numNegative++;
  }
  if (n % 2 == 0 && numNegative % 2 == 1) {
    cout << sum - 2 * sub << endl;
  } else {
    cout << sum << endl;
  }
  return 0;
}
