n = int(input()); s = [input() for _ in range(n)]; a = b = c = d = x = 0
for i in range(n): a += s[i][-i-1]=="A"; b += s[i][-i-1]=="B"; c += s[i][-i-1]=="A"; d += s[i][-i-1]=="B"
x += a==n-1 and b==0; x += c==n-1 and d==0
for i in range(n):
    a = b = c = d = 0
    for j in range(n): a += s[i][j]=="A"; b += s[i][j]=="B"; c += s[j][i]=="A"; d += s[j][i]=="B"
    x += a==n-1 and b==0; x += c==n-1 and d==0
print(x)