#include <bits/stdc++.h>
#define all(x) x.begin(), x.end()
#define ll long long
#define ld long double
#define pb push_back
#define endl '\n'
#define ff first
#define mp make_pair
#define ss second
#define ull unsigned long long
#define YES cout << "YES" << endl;
#define NO cout << "NO" << endl;
#define ulongmax 18446744073709551615
#define pll pair<ll,ll>
using namespace std;

ll maxn = -1e9;
ll minn = 1e9;
ll mod = 1e9 + 7;
const int maxx = 3e6 + 5;
const int base = 311;
ll a[maxx];
int main(){
        ios_base::sync_with_stdio(false);
        cin.tie(0);
        cout.tie(0);
        //freopen("HACK.TXT","r",stdin);
        //freopen(".INP","r",stdin);
        //freopen(".OUT","w",stdout);
        //freopen("HACK.TXT","w",stdout);
        ll n;
        cin >> n;
        for (int i = 1; i <= n; i++){
                cin >> a[i];
        }
        ll mn = 0;
        ll ans = 0;
        ll tong = 0;
        for (int i = 1; i <= n; i++){
                tong = tong + a[i];
                mn = mn + a[i];
                if (mn > 0) mn = 0;
                if (mn < ans) ans = mn;
        }
        cout << (-ans) * 2 + tong;
}
/*
5 2
1 2
2 3
3 4
1 5
5 2
4 1
*/