#include<algorithm>//sort,二分探索,など
#include<bitset>//固定長bit集合
#include<cmath>//pow,logなど
#include<complex>//複素数
#include<deque>//両端アクセスのキュー
#include<functional>//sortのgreater
#include<iomanip>//setprecision(浮動小数点の出力の誤差)
#include<iostream>//入出力
#include<map>//map(辞書)
#include<numeric>//iota(整数列の生成),gcdとlcm(c++17)
#include<queue>//キュー
#include<set>//集合
#include<stack>//スタック
#include<string>//文字列
#include<unordered_map>//イテレータあるけど順序保持しないmap
#include<unordered_set>//イテレータあるけど順序保持しないset
#include<utility>//pair
#include<vector>//可変長配列
using namespace std;

typedef long long ll;

//マクロ
#define REP(i,n) for(ll i=0;i<(ll)(n);i++)
#define REPD(i,n) for(ll i=(ll)(n)-1;i>=0;i--)
#define FOR(i,a,b) for(ll i=(a);i<=(b);i++)
#define FORD(i,a,b) for(ll i=(a);i>=(b);i--)
#define ALL(x) (x).begin(),(x).end() //sortなどの引数を省略したい
#define SIZE(x) ((ll)(x).size()) //sizeをsize_tからllに直しておく
#define MAX(x) *max_element(ALL(x))
#define INF 1000000000000 //10^12
#define MOD 1000000007 //10^9+7
#define MAXR 100000 //10^5:最大のrange(素数列挙などで使用)
struct ArbitraryModInt {

  int x;

  ArbitraryModInt() : x(0) {}

  ArbitraryModInt(int64_t y) : x(y >= 0 ? y % mod() : (mod() - (-y) % mod()) % mod()) {}

  static int &mod() {
    static int mod = 0;
    return mod;
  }

  static void set_mod(int md) {
    mod() = md;
  }

  ArbitraryModInt &operator+=(const ArbitraryModInt &p) {
    if((x += p.x) >= mod()) x -= mod();
    return *this;
  }

  ArbitraryModInt &operator-=(const ArbitraryModInt &p) {
    if((x += mod() - p.x) >= mod()) x -= mod();
    return *this;
  }

  ArbitraryModInt &operator*=(const ArbitraryModInt &p) {
    unsigned long long a = (unsigned long long) x * p.x;
    unsigned xh = (unsigned) (a >> 32), xl = (unsigned) a, d, m;
    asm("divl %4; \n\t" : "=a" (d), "=d" (m) : "d" (xh), "a" (xl), "r" (mod()));
    x = m;
    return *this;
  }

  ArbitraryModInt &operator/=(const ArbitraryModInt &p) {
    *this *= p.inverse();
    return *this;
  }

  ArbitraryModInt operator-() const { return ArbitraryModInt(-x); }

  ArbitraryModInt operator+(const ArbitraryModInt &p) const { return ArbitraryModInt(*this) += p; }

  ArbitraryModInt operator-(const ArbitraryModInt &p) const { return ArbitraryModInt(*this) -= p; }

  ArbitraryModInt operator*(const ArbitraryModInt &p) const { return ArbitraryModInt(*this) *= p; }

  ArbitraryModInt operator/(const ArbitraryModInt &p) const { return ArbitraryModInt(*this) /= p; }

  bool operator==(const ArbitraryModInt &p) const { return x == p.x; }

  bool operator!=(const ArbitraryModInt &p) const { return x != p.x; }

  ArbitraryModInt inverse() const {
    int a = x, b = mod(), u = 1, v = 0, t;
    while(b > 0) {
      t = a / b;
      swap(a -= t * b, b);
      swap(u -= t * v, v);
    }
    return ArbitraryModInt(u);
  }

  ArbitraryModInt pow(int64_t n) const {
    ArbitraryModInt ret(1), mul(x);
    while(n > 0) {
      if(n & 1) ret *= mul;
      mul *= mul;
      n >>= 1;
    }
    return ret;
  }

  friend ostream &operator<<(ostream &os, const ArbitraryModInt &p) {
    return os << p.x;
  }

  friend istream &operator>>(istream &is, ArbitraryModInt &a) {
    int64_t t;
    is >> t;
    a = ArbitraryModInt(t);
    return (is);
  }
};

int main(void){
    int n;
    cin >> n;
    vector<ll> a(n);
    REP(i, n) cin >> a[i];
    
    vector<ll> b(n), c(n);
    b[0] = a[0];
    FOR(i, 1, n-1) {
        b[i] = b[i-1] + a[i];
    }
    c[n-1] = a[n-1];
    for(int i=n-2; i>=0; i--) {
        c[i] = c[i+1] + a[i];
    }
    ll min_d = INF;
    REP(i,n-1) {
        min_d = min(min_d, (ll)abs(b[i]-c[i+1]));
    }
    cout << min_d << endl;
    return 0;
}


Measured memory_bytes: 4992