n = int(input())
an = []
for i in range(n):
    ipt = list(map(int, input().split(' ')))
    if len(ipt) > 1:
        print('\"assert\"')
        exit()
    an.append(ipt[0])

s = sorted(an,reverse=True)

if s[1] == s[2]:
    print(s[1] + s[2])
else:
    print(s[0] + s[2])