import numpy as np

N = int(input())
S = np.array([[s == '.' for s in input()] for _ in range(N)])


def solve(S):
    """左詰め横並べ"""
    left = S[:, -1]
    res = 0
    for i in range(N):
        if np.all(S[i, 1:-1]):
            if S[i, 0]:
                res += 1
            elif S[i, -1]:
                res += 1
                left[i] = False
    if np.all(S[1:-1, -1]) and (S[0, -1] or S[-1, -1]):
        res += 1
    return res


ans = 0
for i in range(4):
    ans = max(ans, solve(S))
    # 回す
    S = np.fliplr(S.T)
print(ans)