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
print(ans)