#include <bits/stdc++.h>
using namespace std;

#define REP(i,m,n) for(int i=(m); i<(int)(n); i++)
#define RREP(i,m,n) for(int i=(int)(n-1); i>=m; i--)
#define rep(i,n) REP(i,0,n)
#define rrep(i,n) RREP(i,0,n)
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
#define fi first
#define se second
#define debug(...) {cerr<<"[L"<<__LINE__<<"] "; _debug(__VA_ARGS__);}

template<typename T>
string join(const vector<T>&v, string del=", "){ stringstream s;
    for(auto x : v) s << del << x; return s.str().substr(del.size());
}
template<typename T>
ostream& operator<<(ostream& o, const vector<T>&v){
    if(v.size()) o << "[" << join(v) << "]"; return o;
}
template<typename T>
ostream& operator<<(ostream& o, const vector<vector<T> >&vv){
    int l = vv.size();
    if(l){ o<<endl; rep(i,l) o << (i==0 ? "[ " : ",\n  " ) << vv[i] << (i==l-1 ? " ]" : ""); }
    return o;
}
template<typename T1, typename T2>
ostream& operator<<(ostream& o, const pair<T1, T2>& p){
    return o << "(" << p.first << ", " << p.second << ")";
}
inline void _debug(){cerr<<endl;}
template<class First, class... Rest>
void _debug(const First& first, const Rest&... rest){cerr<<first<<" ";_debug(rest...);}

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;

const double PI = (1*acos(0.0));
const double EPS = 1e-9;
const int INF = 0x3f3f3f3f;
const ll INFL = 0x3f3f3f3f3f3f3f3fLL;
const ll mod = 1e9 + 7;

inline void finput(string filename) {
    freopen(filename.c_str(), "r", stdin);
}

int main(){
    ios_base::sync_with_stdio(0);
    // finput("./input");
    int n; cin >> n;
    vl a(n);
    rep(i,n) cin >> a[i];
    sort(all(a));

    for(int i=0; i<n-1; i+=2){
        if(a[i]+a[i+1] < 0){
            a[i] = -a[i];
            a[i+1] = -a[i+1];
        }
    }
    ll ans = accumulate(all(a), 0ll);
    cout << ans << endl;
    return 0;
}
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
using vint = vector<int>;
using vvint = vector<vint>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vchar = vector<char>;
using vvchar = vector<vchar>;
using vp = vector<P>;
using vpp = vector<pair<P, P>>;
using vvp = vector<vp>;

#define rep(i, n) for (int i = 0; i < n; ++i)
#pragma region Debug
istream &operator>>(istream &is, P &a)
{
    return is >> a.first >> a.second;
}
ostream &operator<<(ostream &os, const P &a) { return os << "(" << a.first << "," << a.second << ")"; }

template <typename T>

void view(const std::vector<T> &v)
{
#ifndef ONLINE_JUDGE
    for (const auto &e : v)
    {
        std::cout << e << " ";
    }
    std::cout << std::endl;
#endif
}
template <typename T>
void view(const std::vector<std::vector<T>> &vv)
{
    for (const auto &v : vv)
    {
        view(v);
    }
}
#pragma endregion

int main()
{
    int n;
    cin >> n;
    vll a(n);
    rep(i, n) cin >> a[i];
    vll neg;
    ll ans = 0;
    rep(i, n)
    {
        if (a[i] <= 0)
        {
            neg.emplace_back(abs(a[i]));
        }
        ans += abs(a[i]);
    }
    int k = neg.size();

    if (k % 2)
    {
        ll sml = 10000000000;
        rep(i, n) sml = min(sml, abs(a[i]));
        ans -= sml * 2;
    }
    cout << ans << endl;

    return 0;
}