# -*- coding: utf-8 -*-
N = int(input())
A = list(map(int,input().split()))

if len(A) == 3:
    print("\"assert\"")
else:
    A = int(A[0])
    B = int(input())
    C = int(input())
    s = {A + B, B + C, C + A}
    s = list(s)
    s.sort()
    print(s[len(s) - 2])