#include <bits/stdc++.h>
using namespace std;
template <typename T>
T gcd(T a, T b) {
  if (a == 0) return b;
  return gcd(b % a, a);
}
template <typename T>
void read(T &x) {
  register T c = getchar();
  x = 0;
  int t = 0;
  if (c == '-') t = 1, c = getchar();
  for (; (c < 48 || c > 57); c = getchar())
    ;
  for (; c > 47 && c < 58; c = getchar()) {
    x = (x << 1) + (x << 3) + c - 48;
  }
  if (t) x = -x;
}
template <typename T>
T pow(T x, T y) {
  T ans = 1;
  while (y > 0) {
    if (y % 2 == 1) ans = (ans * x) % 1000000007;
    y /= 2;
    x = (x * x) % 1000000007;
  }
  return ans;
}
template <typename T>
long long int roundp(T x) {
  long long int ans = x;
  if (x - floor(x) <= 0.001)
    ans = floor(x);
  else if (ceil(x) - x <= 0.001)
    ans = ceil(x);
  return ans;
}
int main() {
  int n;
  cin >> n;
  int tot = 2 * n - 1;
  vector<int> v(tot);
  int sum = 0, mini = 0x3f3f3f3f, cnt = 0;
  for (long long(i) = (0); i < (tot); i++) {
    cin >> v[i];
    if (v[i] < 0) ++cnt;
    v[i] = abs(v[i]);
    sum += v[i];
    mini = min(mini, v[i]);
  }
  if (cnt % 2 == 0 || n % 2 == 1) {
    cout << sum;
    return 0;
  }
  cout << sum - 2 * mini;
}
