import copy
N = int(input())
lsS = [list(input()) for i in range(N)]
def rotate(ls):
    lens = len(ls)
    ret = [[0]*lens for i in range(lens)]
    for i in range(lens):
        for j in range(lens):
            ret[j][lens-1-i] = ls[i][j]
    return ret
ans = 0
for i in range(4):
    ls2 = copy.deepcopy(lsS)
    cnt = 0
    for j in range(1,N-1):
        if ls2[j][:-1].count('.') == N-1:
            cnt += 1
            for k in range(N-1):
                ls2[j][k] = '#'
        if ls2[j][1:].count('.') == N-1:
            cnt += 1
            for k in range(1,N):
                ls2[j][k] = '#'
    
    if ls2[0].count('#') == 0 and ls2[-1].count('#') == 0:
        cnt += 2
        for k in range(N-1):
            ls2[0][k] = '#'
            ls2[-1][k+1] = '#'

    for j in range(N):
        cc = 0
        for k in range(N):
            if ls2[k][j] == '#':
                cc += 1
        if cc == 0:
            cnt += 1
        if cc == 1 and (ls2[0][j] == '#' or ls2[-1][j] == '#'):
            cnt += 1

    ans = max(ans, cnt)
    lsS = rotate(lsS)
print(ans)