N = int(input())
l = list(map(int,input().split()))
if len(l) > 1:
    print('"assert"')
else:
    a = l[0]
    b = int(input())
    c = int(input())
    s = {a + b,b + c,a + c}
    s = sorted(s,reverse = True)
    print(s[1])