n = int(input())
al = [ int(v) for v in input().split() ]
if len(al) == 3:
    print("assert")
else:
    a = al[0]
    b = int(input())
    c = int(input())
    bl = list(set([a + b, b + c, c + a]))
    bl.sort(reverse = True)
    print(bl[1])