with open('1.txt','r') as f:
    lines = f.read().split('\n')

n = int(lines[0])
a = []
for i in lines[1:]:
    a.append([i.split()[0], i.split()[1]])


minS = 100000*2*10000

for i in range(2**n):
    t = bin(i)[2:]
    if len(t) != n:
        t = list('0'*(n-len(t))+t)

    else:
        t = list(t)

    num = 0
    s = 0


    for j in t:

        s += int(a[num][int(j)])
        num += 1

    if s % 3 != 0 and s < minS:
        minS = s
print(minS)