#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, a[250];
  scanf("%d", &n);
  m = 2 * n - 1;
  for (int i = 0; i < m; i++) {
    scanf("%d", &a[i]);
  }
  if (n % 2 == 1) {
    int ans = 0;
    for (int i = 0; i < m; i++) {
      ans += fabs(a[i]);
    }
    printf("%d", ans);
  } else {
    int ans = 0, f = 0;
    for (int i = 0; i < m; i++) {
      if (a[i] < 0) {
        f++;
        a[i] = -a[i];
      }
    }
    if (f == 0 || f % 2 == 0) {
      for (int i = 0; i < m; i++) ans += a[i];
      printf("%d", ans);
    } else if (f % 2 == 1) {
      int minn = 99999;
      for (int i = 0; i < m; i++) {
        ans += a[i];
        minn = min(minn, a[i]);
      }
      ans -= 2 * minn;
      printf("%d", ans);
    }
  }
  return 0;
}
