n = input()
li = list(map(int,input().split()))	
if len(li) >= 2:
    print("\"assert\"")
else :
    a = int(input())
    b = int(input())
    c = li[0]
    li = [a+b,b+c,c+a]
    li = sorted(list(set(li)))
    print(li[len(li)-2])