from collections import deque

def check(row, col, a, color, q):
    empty = 0
    if not color[row][col]:
        if a[row + 1][col] == '.':
            empty += 1
            if not color[row + 1][col]:
                q.append(row + 1)
                q.append(col)
        if a[row - 1][col] == '.':
            empty += 1
            if not color[row - 1][col]:
                q.append(row - 1)
                q.append(col)
        if a[row][col + 1] == '.':
            empty += 1
            if not color[row][col + 1]:
                q.append(row)
                q.append(col + 1)
        if a[row][col - 1] == '.':
            empty += 1
            if not color[row][col - 1]:
                q.append(row)
                q.append(col - 1)
        color[row][col] = 1
        return 4 - empty
    return 0

n = int(input())
a = [['*'] * (n+2) for i in range(n + 2)]
color = [[0] * (n+2) for i in range(n + 2)]

for i in range(1, n + 1):
    row = input()
    for j in range(1, n + 1):
        a[i][j] = row[j - 1]

q = deque()
q.append(1)
q.append(1)
walls = 0

while q:
    row = q.popleft()
    col = q.popleft()
    walls += check(row, col, a, color, q)

if not color[n][n]:
    q.append(n)
    q.append(n)
    while q:
        row = q.popleft()
        col = q.popleft()
        walls += check(row, col, a, color, q)

walls -= 4
m = walls * 9
print(m)