#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>

#include <algorithm>
#include <bitset>
#include <complex>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#include <cassert>
#include <functional>

typedef long long ll;
using namespace std;

#ifndef LOCAL
#define debug(...) ;
#else
#define debug(...) cerr << __LINE__ << " : " << #__VA_ARGS__ << " = " << _tostr(__VA_ARGS__) << endl;

template<typename T>
ostream &operator<<(ostream &out, const vector<T> &v);

template<typename T1, typename T2>
ostream &operator<<(ostream &out, const pair<T1, T2> &p) {
  out << "{" << p.first << ", " << p.second << "}";
  return out;
}

template<typename T>
ostream &operator<<(ostream &out, const vector<T> &v) {
  out << '{';
  for (const T &item : v) out << item << ", ";
  out << "\b\b}";
  return out;
}

void _tostr_rec(ostringstream &oss) {
  oss << "\b\b \b";
}

template<typename Head, typename... Tail>
void _tostr_rec(ostringstream &oss, Head &&head, Tail &&... tail) {
  oss << head << ", ";
  _tostr_rec(oss, forward<Tail>(tail)...);
}

template<typename... T>
string _tostr(T &&... args) {
  ostringstream oss;
  int size = sizeof...(args);
  if (size > 1) oss << "{";
  _tostr_rec(oss, forward<T>(args)...);
  if (size > 1) oss << "}";
  return oss.str();
}
#endif

#define mod 1000000007 //1e9+7(prime number)
#define INF 1000000000 //1e9
#define LLINF 2000000000000000000LL //2e18
#define SIZE 200010

ll dp[SIZE][2];

int main() {
  int N, A[SIZE];

  cin >> N;
  for (int i = 0; i < N; i++) cin >> A[i];

  for (int i = 0; i <= N; i++) dp[i][0] = dp[i][1] = -LLINF;
  dp[0][0] = 0;

  for (int i = 0; i < N; i++) {
    dp[i + 1][0] = max(dp[i][0] + A[i], dp[i][1] - A[i]);
    dp[i + 1][1] = max(dp[i][0] - A[i], dp[i][1] + A[i]);
  }

  cout << dp[N][0] << endl;

  return 0;
}
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <queue>
#include <cstring>
#include <vector>
#include <map>
#include <algorithm>
#include <cctype>
#include <cmath>
#include <bitset>
#include <set>
#include <stack>
using namespace std;

#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define RREP(i,n) for(int i=n-1;i>=0;i--)
#define FOR(i,k,n) for(int i=(k);i<(int)(n);i++)
#define all(i,n) (i),(i+n)

int dx4[4]={1,0,-1,0};
int dy4[4]={0,-1,0,1};
int dx8[8]={1,0,-1,1,-1,1,0,-1};
int dy8[8]={1,1,1,0,0,-1,-1,-1};
int dx9[9]={0,1,0,-1,1,-1,1,0,-1};
int dy9[9]={0,1,1,1,0,0,-1,-1,-1};

typedef pair<int, int> P;
typedef pair<string, int> SP;
typedef long long ll;
typedef pair<ll, ll> PLL;

const int INF = 1e9;
const ll LLINF = 1e18;
const int MAX_V = 1e6+1;
const ll mod = 1000000007;
// << fixed << setprecision
// --------------------------------------
int n;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  cin >> n;
  vector<ll> a(n);

  int c = 0;
  ll sum = 0;
  REP(i, n) {
    cin >> a[i];
    sum += abs(a[i]);
    if(a[i] < 0) c++;
  }

  if(c % 2 == 1) {
    ll mi = INF;
    REP(i, n)  {
      mi = min(abs(a[i]), mi);
    }
    sum -= (mi * 2);
  }

  cout << sum << endl;
}
