#include <bits/stdc++.h>
using namespace std;
typedef vector<long long> vl;
typedef complex<double> C;
void fft(vector<C>& F, bool inv) {
  const double PI = acos(-1.);
  for (int x = 1; x < F.size(); x <<= 1) {
    vector<C> G = F;
    int d = F.size() / (2 * x);
    for (int i = 0; i < F.size() / 2; i++) {
      auto u = F[i + i / d * d], v = F[i + i / d * d + d];
      G[i] = u + v * polar(1., (inv ? -1 : 1) * PI * (i / d) / x);
      G[i + F.size() / 2] = u - v * polar(1., (inv ? -1 : 1) * PI * (i / d) / x);
    }
    F = G;
  }
  if (inv) for(auto& v : F) v /= F.size();
}
vl conv(const vl& f,const vl& g) {
  if (f.empty() || g.empty()) return {};
  int n = 1;
  while (n <= f.size() + g.size()) n <<= 1;
  vector<C> F(n), G(n);
  for (int i = 0; i < f.size(); i++) F[i] = f[i];
  for (int i = 0; i < g.size(); i++) G[i] = g[i];
  fft(F, false);
  fft(G, false);
  vector<C> H(n);
  for (int i = 0; i < n; i++) H[i] = F[i] * G[i];
  fft(H, true);
  vl h(f.size() + g.size() - 1);
  for (int i = 0; i < h.size(); i++) h[i] = round(H[i].real());
  return h;
}
int main(){
  int X, Y, Z;
  cin >> Z >> Y >> X;
  vl SB(8 * X * Y * Z), SW(8 * X * Y * Z), TB(8 * X * Y * Z), TW(8 * X * Y * Z);
  for (int x = 0; x < X; x++) {
    for (int y = 0; y < Y; y++) {
      string S;
      cin >> S;
      for (int z = 0; z < Z; z++) {
        int t = z + 2 * Z * y + 4 * Y * Z * x;
        if (S[z] == 'B') {
          SB[t] = 1;
          SB[t + Z] = 1;
          SB[t + 2 * Y * Z] = 1;
          SB[t + 2 * Y * Z + Z] = 1;
          SB[t + 4 * X * Y * Z] = 1;
          SB[t + 4 * X * Y * Z + Z] = 1;
          SB[t + 4 * X * Y * Z + 2 * Y * Z] = 1;
          SB[t + 4 * X * Y * Z + 2 * Y * Z + Z] = 1;
        }
        if (S[z] == 'W') {
          SW[t] = 1;
          SW[t + Z] = 1;
          SW[t + 2 * Y * Z] = 1;
          SW[t + 2 * Y * Z + Z] = 1;
          SW[t + 4 * X * Y * Z] = 1;
          SW[t + 4 * X * Y * Z + Z] = 1;
          SW[t + 4 * X * Y * Z + 2 * Y * Z] = 1;
          SW[t + 4 * X * Y * Z + 2 * Y * Z + Z] = 1;
        }
      }
    }
  }
  for (int x = 0; x < X; x++) {
    for (int y = 0; y < Y; y++) {
      string T;
      cin >> T;
      for (int z = 0; z < Z; z++) {
        int t = z + 2 * Z * y + 4 * Y * Z * x;
        if (T[z] == 'B') TB[t] = 1;
        if (T[z] == 'W') TW[t] = 1;
      }
    }
  }
  reverse(TB.begin(), TB.end());
  reverse(TW.begin(), TW.end());
  auto P = conv(SW, TB);
  auto Q = conv(SB, TW);
  int ans = X * Y * Z;
  for (int x = 0; x < X; x++) {
    for (int y = 0; y < Y; y++) {
      for (int z = 0; z < Z; z++) {
      	int t = z + 2 * Z * y + 4 * Y * Z * x;
      	t += 8 * X * Y * Z - 1;
        ans = min(ans, int(P[t] + Q[t]));
      }
    }
  }
  cout << ans << endl;
  return 0;
}