s = int(input())
a = list(map(int,input().split()))
if len(a) > 1:
  print("\"assert\"")
else:
  a = a[0]
  b = int(input())
  c = int(input())
  x = [a+b,b+c,c+a]
  x = list(set(x))
  x.sort()
  print(x[len(x)-2])