N = int(input())
S = [input() for i in range(N)]
T = ""
for i in range(N):
    T += S[i]
maxeye = -1
eyen = -1
for i in range(1000):
    x = T.count("(" + "^" * i + ")")
    if x >= maxeye:
        maxeye = x
        eyen = i
print(eyen)