import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################

from bisect import bisect_left as bl
def g(d):
    if n % 2:
        dp = [0]*(2+n)
        for i in range(n,-1,-1):
            dp[i] = dp[bl(x,x[i]+d)] + bl(x,x[i]+d)-i-1
        #print(dp)
        if dp[0] <= n//2:
            return 1
        else:
            return 0
    else:
        z = 0
        for i in range(n):
            z = max(z, bl(x, x[i]+d)-i-1)
        #print(z)
        if z > n//2:
            return 0
        else:
            return 1

n = ni()
a = na()
x = [0]
for i in range(n):
    x.append(x[-1]+a[i])
ok = 0
ng = 10**14+1
while ng-ok>1:
    d = ok+ng>>1
    if g(d):
        ok= d
    else:
        ng = d
print(ok)