#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  while (scanf("%d", &n) != EOF) {
    int sum = 0;
    int minNum = 1 << 30;
    int cnt = 0;
    int x;
    for (int i = 0; i < 2 * n - 1; i++) {
      scanf("%d", &x);
      sum += abs(x);
      if (x < 0) cnt++;
      minNum = min(minNum, abs(x));
    }
    if (n & 1)
      printf("%d\n", sum);
    else {
      if (cnt & 1)
        printf("%d\n", sum - 2 * minNum);
      else
        printf("%d\n", sum);
    }
  }
  return 0;
}
