n = int(input())
S = [list(input()) for _ in range(n)]
#print(S)
#print([r[0] for r in S])
ans = 0
#hoizon check
for i in range(n):
    if "B" in S[i]:
        #print(S[i])
        continue;
    count = S[i].count('.')
    #count = len([s for s in S[i] if "." in S[i]])
    if count == 1:
        #print(S[i])
        ans = ans+1

#vertical check
for i in range(n):
    if "B" in [r[i] for r in S]:
        #print([r[i] for r in S])
        continue;
    #print([r[i] for r in S])
    VS=[r[i] for r in S]
    #print(VS)
    count = VS.count('.')
    #print(count)
    if count == 1:
        #print(S[i])
        ans = ans+1

# naname
rl_d = [[S[max(0, -d) + i][max(0, d) + i] for i in range(n - abs(d))] for d in range(1-n, n)]
#print(rl_d[n-1])
if "B" in rl_d[n-1]:
    a=1
elif rl_d[n-1].count('.') == 1:
    ans = ans +1
lr_d = [[S[max(0, d) + i][min(n + d, n) - i - 1] for i in range(n - abs(d))] for d in range(1 - n, n)]
#print(lr_d)
if "B" in lr_d[n-1]:
    a=1
elif lr_d[n-1].count('.') == 1:
    ans = ans +1
print(ans)