#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a = -1001, m = 1001, tong = 0;
  cin >> n;
  if (n % 2 == 1) {
    for (int i = 0; i <= 2 * n - 2; i++) {
      int b;
      cin >> b;
      if (b < 0) b = -b;
      tong = tong + b;
    }
  } else {
    int count = 0;
    for (int i = 0; i <= 2 * n - 2; i++) {
      int b;
      cin >> b;
      if (b < 0) {
        count = count + 1;
        if (b > a) a = b;
        b = -b;
      } else {
        if (b < m) m = b;
      }
      tong = tong + b;
    }
    if (count % 2 == 1) {
      if ((-a) <= m)
        tong = tong + a + a;
      else
        tong = tong - m - m;
    }
  }
  cout << tong;
  return 0;
}
