#include <bits/stdc++.h>
using namespace std;
int ls[420];
inline int abs(int a) { return (a < 0) ? -a : a; }
int main() {
  int i, j;
  int n, k;
  scanf("%d", &k);
  n = 2 * k - 1;
  int neg = 0, pos = 0, zer = 0;
  for (i = 0; i < n; i++) {
    scanf("%d", &ls[i]);
    if (ls[i] < 0)
      neg++;
    else if (ls[i] > 0)
      pos++;
    else
      zer++;
  }
  int sum = 0;
  if (zer || k % 2) {
    for (i = 0; i < n; i++) {
      if (ls[i] < 0)
        sum += ls[i] * -1;
      else
        sum += ls[i];
    }
  } else {
    if (neg % 2) {
      int ps = 0;
      for (i = 0; i < n; i++)
        if (abs(ls[i]) < abs(ls[ps])) ps = i;
      for (i = 0; i < n; i++) {
        if (i == ps) {
          sum += -abs(ls[i]);
          continue;
        }
        if (ls[i] < 0)
          sum += ls[i] * -1;
        else
          sum += ls[i];
      }
    } else {
      for (i = 0; i < n; i++) {
        if (ls[i] < 0)
          sum += ls[i] * -1;
        else
          sum += ls[i];
      }
    }
  }
  printf("%d\n", sum);
  return 0;
}
