#include <bits/stdc++.h>
using namespace std;
const int maxn = 200;
int a[maxn];
int main(void) {
  int n;
  while (cin >> n) {
    int sum = 0, neg = 0, minNeg = 0x3f3f3f3f;
    for (int i = 0; i < 2 * n - 1; i++) {
      scanf("%d", &a[i]), sum += abs(a[i]);
      if (a[i] <= 0) neg++;
      minNeg = a[i] <= 0 ? min(minNeg, -a[i]) : min(minNeg, a[i]);
    }
    if (n % 2 || neg % 2 == 0)
      printf("%d\n", sum);
    else
      printf("%d\n", sum - minNeg * 2);
  }
  return 0;
}
