27 задание

f = open('27-B.txt')
n = int(f.readline())
def get():
    return list(map(int, f.readline().split()))

s = get()

for i in range(n-1):
    para = get()
    cmb = [a + b for a in s for b in para]
    s1 =[0]*4
    for x in cmb:
        s1[x%3] = max(s1[x%3], x)
    s = [ x for x in s1 if x != 0]

m = 0
for x in s:
    if x % 3 != 0 and x > m:
        m = x
print(m)