#include<bits/stdc++.h>
#define fr(i,j,n)   for(int i=j;i<n;i++)
#define pb          push_back
#define rf(i,j,p)   for(int i=p-1;i>=j;i--)
#define vi          vector<int>
#define vll         vector<long long>
#define ll          long long
#define hmm         "\n"
#define sp          " "
#define srt(v)      sort(v.begin(), v.EEnd());
#define ww           int tc ; cin >> tc ; while(tc--)
#define down        cout<<hmm;
#define faaast      ios_base::sync_with_stdio(0);cin.tie(nullptr);
#include <iostream>
#include <fstream>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
//#define ordered_set tree<pair<ll,ll>, null_type,less<pair<ll,ll>>, rb_tree_tag,tree_order_statistics_node_update>
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
//template<class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
ll max_so_far, max_EEnding_here ;
ll start, EEnd , s;
bool allneg(ll a[], int n)
{
  fr(i,0,n)
  {
    if(a[i]>0)return 0;
  }
  return 1;
}
bool allpos(ll a[], int n)
{
  fr(i,0,n)
  {
    if(a[i]<0)return 0;
  }
  return 1;
}


void maxSubArraySum(ll a[], int size)
{
    
  start =0, EEnd = 0, s=0;
  max_so_far = LLONG_MIN, max_EEnding_here = 0;
    for (int i=0; i< size; i++ )
    {
        max_EEnding_here += a[i];
  
        if (max_so_far < max_EEnding_here)
        {
            max_so_far = max_EEnding_here;
            start = s;
            EEnd = i;
        }
  
        if (max_EEnding_here < 0)
        {
            max_EEnding_here = 0;
            s = i + 1;
        }
    }
    //max so far , EEnd ;
}
int main()
{
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
  
  int n  ; cin >> n  ; 
  ll arr[n]; ll cum[n];
  fr(i,0,n)cin >> arr[i], cum[i]=arr[i];
  maxSubArraySum( arr, n);
  //cout<<start<<sp<<EEnd<<hmm; 
  if((start == 0 && EEnd == n-1)||allneg(arr, n)|| allpos(arr,n)){
    fr(i,1,n)cum[i]+=cum[i-1];
    ll mx = 0 ; 
    mx = abs(cum[n-1]-(ll)2*arr[0]);
    mx = max(mx , abs(cum[n-1]-(ll)2*arr[n-1]));
    fr(i,1,n-1){
      mx = max(mx ,abs(cum[i-1]-arr[i]));
      mx = max(mx, abs(cum[n-1]-cum[i]-arr[i]));
       
    }
    cout<<mx<<hmm;
    return 0;
  }

  
  ll mx = 0, sum=0 ; 
  for(int i = start -1 ; i >=0 ; i--){
    sum += arr[i];
    mx = max(mx, abs(max_so_far-sum));  
  }
  sum = 0 ; 
  fr(i,EEnd+1, n)
  {
    sum += arr[i];
    mx = max(mx, abs(max_so_far-sum));
  }
  cout<<mx<<hmm; 
}