#include <bits/stdc++.h>
using namespace std;
int N;
int main() {
  while (scanf("%d", &N) == 1) {
    bool hasZero = false;
    int negative = 0, sum = 0, mn = 2147483647;
    for (int i = 0, v; i < N * 2 - 1; i++) {
      assert(scanf("%d", &v) == 1);
      if (v == 0)
        hasZero = true;
      else {
        if (v < 0) negative++, v = -v;
      }
      assert(v >= 0);
      sum += v;
      if (v < mn) mn = v;
    }
    int ans;
    if (hasZero)
      ans = sum;
    else {
      ans = (negative % 2 == 0 || N % 2 == 1 ? sum : sum - mn * 2);
    }
    printf("%d\n", ans);
  }
  return 0;
}
