#include <bits/stdc++.h>
using namespace std;
void RI(int& x) {
  x = 0;
  char c = getchar();
  while (!(c >= '0' && c <= '9' || c == '-')) c = getchar();
  bool flag = 1;
  if (c == '-') {
    flag = 0;
    c = getchar();
  }
  while (c >= '0' && c <= '9') {
    x = x * 10 + c - '0';
    c = getchar();
  }
  if (!flag) x = -x;
}
void RII(int& x, int& y) { RI(x), RI(y); }
void RIII(int& x, int& y, int& z) { RI(x), RI(y), RI(z); }
void RC(char& c) {
  c = getchar();
  while (c == ' ' || c == '\n') c = getchar();
}
char RC() {
  char c = getchar();
  while (c == ' ' || c == '\n') c = getchar();
  return c;
}
const long long mod = 1e9 + 7;
const long long LINF = 1e18;
const int INF = 1e9;
const double EPS = 1e-8;
int main() {
  int n, sum = 0, num = 0, minn = INF;
  RI(n);
  for (int i = 1; i <= 2 * n - 1; i++) {
    int t;
    RI(t);
    if (t < 0) num++;
    sum += abs(t);
    minn = min(minn, abs(t));
  }
  if (n % 2 == 0 && num % 2 == 1) {
    sum -= 2 * minn;
  }
  cout << sum << endl;
}
