/*                    `
                                    `.:ossyyyyysssssyyyyyyhyyyhyyyyysssooo+//:-.```
                                   -sdNNMMMMMMNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNmmdhhyso+/-.``
                                  `odNNNmmdhysoo+//////::::::::::::://///+ooosyyhhdmmmNmmhs+:-.`
                                   .--:/oo+:```                           ``````...--:/oshdmmmdyo/-`
                                   `.:oymd+.                                            ``-:/ohdNNmhs/-.`
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                              `-ohNMMNho-`                                                       `-/oydNMNmdyo/-`
                            `:smNMMNdo-`                                                            ``-/oydmNNNmhs/.`
                           .odNMMNh+-`                                                                   `-/+shmNNmdyo:.`
                         `:hNMNmy/.`                                                                         `.-+ydNNNNdo:.`
                        `+dNMmy/.                                                                               `.-/shNMNmhs:.
                       .+mMNh/.                                                                                     `./shNMMmh+-`
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                     `+mMms.                                                                                              .:odNMNmo-`
                     -hNNy-                                                                                                 `-odNMNdo-
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                   `:mMNy-                                                                                                      `/hmMMNh/`
                   .hNMNs.                                                                                                        .+dNMMms-`
                   -mMMmo`                                                                                                         `-smNMNd+.
                  `/NMMd/                                                                `.-://:-..`                                 ./hNMMNy:`
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                .sNMMNo.                                                                                                                              `smMm/`
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                                `:hNMms-`                                                                                                               :yMMNy-                                                                                            `-`
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                                                  `.:sdNNNNdy+-``                                                                       `.:ohmNNms:`                                       `:/-:/+ooo/.` ./shhs+-   `:oydho-``:sysoooydyo-` `-//+ooo/.`
                                                     `./sdNMMNmho/-`                                                                `.-/shmNMmh+-`                                         .+ss:` `./hy:` `-yh:`      .+ds.    .+-` .omo.  .+s:` `./hh:`
                                                        `-+hmNMMNNdy+-``                                                        ``-/ohmNNNmds:.                                            .smo`    `+my-  -yh/..```  `+ho.    `/-` .om+` `+ho`    .+my-
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                                                                 `.:+ydmNNNNNNNNNNNNNNmmmmmmmmmmmNNNNNNNmmmmmmmdddmmmmmmNNNNNNNmdy+:.`                                                      `:yy/-..:o+.  ./hh/..:odo-.+ds.`:+/:/```:sNs-` `/hy/-..:o+.
                                                                     ``.:/++oooo++//::--.......-:/ymmdmds+++++++++++++++++++++/:.`                                                            .:+o+/-.`  .:ossooo+/:.`-+s+-.:oo:. `/osyso-` `.:+o+/:.`
                                                                                                 .sdddh/`
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                                                                                                   `:hdddh+`
                                                                                                    .+dddds-
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                                                                                                     `/hdddy.
                                                                                                      .ydddh/`
                                                                                                      `ohddho`
                                                                                                      `+hdddo`
                                                                                                      `+hddho`
                                                                                                      `/yhhs:`

*/

#include<bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define rng(a) a.begin(),a.end()
#define int long long
using namespace std;
typedef long long ll;





main(){
int n;
cin >> n;
vector<int> a(n);
bool if0 = 0;
int ce = 0;
int sum = 0;
for(int i = 0;i<n;i++){
    cin >> a[i];
    if(a[i]==0) if0 = 1;
    if(a[i]<0) ce++;
    a[i] = abs(a[i]);
    sum += a[i];
}
if(if0){
    cout << sum << endl;
    return 0;
}
if(ce%2==0){
    cout << sum << endl;
    return 0;
}
int minx = 1e9;
for(int i = 0;i<n;i++){
    minx = min(a[i],minx);
}
cout << sum - 2*minx;
}


Measured memory_bytes: 1024