n = int(input())
A = list(map(int, input().split()))
if len(A) == 3:
	print('"assert"')
	exit(0)
B = int(input())
C = int(input())
S = [A[0], B, C]
hoge = set()
for i in range(3):
	for j in range(i + 1, 3):
		hoge.add(S[i] + S[j])
print(sorted(list(hoge))[::-1][1])