n = int(input())
a = list(map(int, input().split()))

if len(a) > 1:
    print('"assert"')
    exit()

for i in range(2):
    a.append(int(input()))

b = set()
b.add(a[0] + a[1])
b.add(a[0] + a[2])
b.add(a[1] + a[2])

c = list(b)
c.sort()
c.reverse()

print(c[1])