#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define AquA cin.tie(0);ios_base::sync_with_stdio(0);
#define fs first
#define sc second
#define p_q priority_queue
#define int long long
using namespace std;

signed main(){
    AquA;
    int n;
    cin >> n;
    vector<int> v(n+1);
    for(int i=1;i<=n;i++){
        cin >> v[i];
        v[i]+=v[i-1];
    }
    vector<int> ax(v),bx(v),an(v),bn(v);
    for(int i=1;i<=n;i++){
        ax[i]=max(ax[i-1],ax[i]);
        an[i]=min(an[i-1],an[i]);
    }
    for(int i=n-1;i>=0;i--){
        bx[i]=max(bx[i+1],bx[i]);
        bn[i]=min(bn[i+1],bn[i]);
    }
    int ans=0;
    for(int i=1;i<n;i++){
        ans=max(ans,abs((v[i]-ax[i-1])-(bx[i+1]-v[i])));
        ans=max(ans,abs((v[i]-an[i-1])-(bx[i+1]-v[i])));
        ans=max(ans,abs((v[i]-ax[i-1])-(bn[i+1]-v[i])));
        ans=max(ans,abs((v[i]-an[i-1])-(bn[i+1]-v[i])));
    }
    cout << ans << "\n";
	return 0;
}