#include <bits/stdc++.h>
using namespace std;
const int N = 201000;
int main() {
  int i, j, T, t, n, m, a, b, sum;
  while (cin >> n) {
    sum = 0;
    int xiao = 0, min = 0x7f7f7f7f;
    for (i = 0; i < 2 * n - 1; i++) {
      scanf("%d", &a);
      if (a < 0) {
        xiao++;
        a = -a;
      }
      sum += a;
      if (a < min) min = a;
    }
    if (n & 1)
      printf("%d\n", sum);
    else {
      if (xiao & 1)
        printf("%d\n", sum - 2 * min);
      else
        printf("%d\n", sum);
    }
  }
  return 0;
}
