#include <bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define mofile(s) freopen(s,"r",stdin)
#define outfile(s) freopen(s,"w",stdout)
#define ll long long
#define ii pair<int,int>
#define iii pair<int,ii>
#define fi first
#define se second
#define tf bool
#define ST stack
#define DQ deque
#define Q queue
#define S string
#define Ma map
#define UM unordered_map
#define SE set
#define str(x) to_string(x)
#define all(a) (a).begin(),(a).end()
#define FOR(i,l,r,d) for(int i=l;i<=r;i+=d)
#define FOD(i,l,r,d) for(int i=r;i>=l;i-=d)
#define xuong cout<<"\n"
#define debug(x) cout<<(x)<<" "
#define ppcnt(x) __builtin_popcountll(x)
#define parity(x) __builtin_parityll(x)
#define lead0(x) __builtin_clzll(x)
#define LOG2 __lg(x)
#define tr0(x) __builtin_ctzll(x)
#define fiset(x) __builtin_ffsll(x)
#define MASK(k) (1LL<<(k))
#define BIT(x,k) ((x)>>(k)&1)
#define pb push_back
#define tron(x) setprecision(x)
#define het return 0
#define base_ 1000000000
const int maxn=1e6+5;
const ll tle=2e8;
const int base=31;
string bcc="abcdefghijklmnopqrstuvwxyz";
int dx[]={-1,0,1,0};
int dy[]={0,1,0,-1};
bool sang[10000005];
ll pref[1005][1005],mt[1005][1005];
void sieve(){
    for(int i=1;i<=10000000;++i) sang[i]=1;
    sang[0]=sang[1]=0;
    for(int i=2;i*i<=10000000;++i){
        if(sang[i]){
            for(int j=i*i;j<=10000000;j+=i) sang[j]=0;
        }
    }
}
void lis(){
    vector<int>t;
    vector<int>a;
    int n; cin>>n;
    for(int i=1;i<=n;++i){
        int ai; cin>>ai;
        a.pb(ai);
    }
    for(int x:a){
        auto it=lower_bound(all(t),x);
        if(it==t.end()) t.pb(x);
        else *it=x;
    }
}
void pfs2d(){
    int n,m,k; cin>>n>>k; m=n;
    for(int i=1;i<=n;++i){
        for(int j=1;j<=m;++j) cin>>mt[i][j];
    }
    for(int i=1;i<=n;++i){
        for(int j=1;j<=m;++j) pref[i][j]=mt[i][j]+pref[i-1][j]+pref[i][j-1]-pref[i-1][j-1];
    }
}
ll qu2d(int x1,int y1,int x2,int y2){
    return pref[x2][y2]-pref[x1-1][y2]-pref[x2][y1-1]+pref[x1-1][y1-1];
}
void open(){
    if(fopen("tongARTKEY.INP","r")){
        mofile("tongARTKEY.INP");
        outfile("tongARTKEY.OUT");
    }
}
ll pfs[maxn],a[maxn];
map<ll,ll>c;
ll ans=-1e18;
int main(){
    fast;
    int n; cin>>n;
    for(int i=1;i<=n;++i) cin>>a[i];
    for(int i=1;i<=n;++i) pfs[i]=pfs[i-1]+a[i];
    for(int i=1;i<=n;++i) ans=max({ans,(-1ll)*(pfs[n]-pfs[i])+pfs[i],(pfs[n]-pfs[i])+pfs[i]*(-1ll)});
    cout<<ans<<"\n";
    het;
}