#include <bits/stdc++.h>
using namespace std;
char c[10][10];
int ans;
int main() {
  cin >> c[1] >> c[2] >> c[3] >> c[4] >> c[5] >> c[6] >> c[7] >> c[8];
  for (int i = 1; i <= 8; i++) {
    int p = 0;
    for (int j = 0; j < 8; j++)
      if (c[i][j] == 'B') p++;
    if (p == 8) ans++;
    p = 0;
    for (int j = 1; j <= 8; j++)
      if (c[j][i - 1] == 'B') p++;
    if (p == 8) ans++;
  }
  if (ans != 16)
    cout << ans;
  else
    cout << 8;
  return 0;
}
