#include <bits/stdc++.h>
using namespace std;
const int INF = 1000000000;
struct Edge {
  int a, b, cap, flow;
};
struct MaxFlow {
  int n, s, t;
  vector<int> d, ptr, q;
  vector<Edge> e;
  vector<vector<int> > g;
  MaxFlow(int n) : n(n), d(n), ptr(n), g(n), q(n) {
    e.clear();
    for (int i = 0, _a = (n); i < _a; i++) {
      g[i].clear();
      ptr[i] = 0;
    }
  }
  void addEdge(int a, int b, int cap) {
    Edge e1 = {a, b, cap, 0};
    Edge e2 = {b, a, 0, 0};
    g[a].push_back((int)e.size());
    e.push_back(e1);
    g[b].push_back((int)e.size());
    e.push_back(e2);
  }
  int getMaxFlow(int _s, int _t) {
    s = _s;
    t = _t;
    int flow = 0;
    for (;;) {
      if (!bfs()) break;
      for (int i = 0, _a = (n); i < _a; i++) ptr[i] = 0;
      while (int pushed = dfs(s, INF)) flow += pushed;
    }
    return flow;
  }

 private:
  bool bfs() {
    int qh = 0, qt = 0;
    q[qt++] = s;
    for (int i = 0, _a = (n); i < _a; i++) d[i] = -1;
    d[s] = 0;
    while (qh < qt && d[t] == -1) {
      int v = q[qh++];
      for (int i = 0, _a = (g[v].size()); i < _a; i++) {
        int id = g[v][i], to = e[id].b;
        if (d[to] == -1 && e[id].flow < e[id].cap) {
          q[qt++] = to;
          d[to] = d[v] + 1;
        }
      }
    }
    return d[t] != -1;
  }
  int dfs(int v, int flow) {
    if (!flow) return 0;
    if (v == t) return flow;
    for (; ptr[v] < (int)g[v].size(); ++ptr[v]) {
      int id = g[v][ptr[v]], to = e[id].b;
      if (d[to] != d[v] + 1) continue;
      int pushed = dfs(to, min(flow, e[id].cap - e[id].flow));
      if (pushed) {
        e[id].flow += pushed;
        e[id ^ 1].flow -= pushed;
        return pushed;
      }
    }
    return 0;
  }
};
const int di[] = {-1, 1, 0, 0};
const int dj[] = {0, 0, -1, 1};
int n, t, startx, starty;
char scientistMap[22][22], locationMap[22][22];
int d[22][22][22][22];
void bfs(int turn, int u, int v) {
  int curu = u, curv = v;
  queue<int> qu, qv;
  qu.push(u);
  qv.push(v);
  d[u][v][u][v] = 0;
  while (!qu.empty()) {
    u = qu.front();
    qu.pop();
    v = qv.front();
    qv.pop();
    for (int dir = 0, _a = (4); dir < _a; dir++) {
      int uu = u + di[dir], vv = v + dj[dir];
      if (uu < 1 || uu > n || vv < 1 || vv > n || locationMap[uu][vv] == 'Y')
        continue;
      if (d[curu][curv][uu][vv] >= 0) continue;
      if (turn && d[startx][starty][uu][vv] >= 0 &&
          d[curu][curv][u][v] + 1 > d[startx][starty][uu][vv])
        continue;
      if (turn && d[startx][starty][uu][vv] >= 0 &&
          d[curu][curv][u][v] + 1 == d[startx][starty][uu][vv]) {
        if (locationMap[uu][vv] >= '1' && locationMap[uu][vv] <= '9') {
          d[curu][curv][uu][vv] = d[curu][curv][u][v] + 1;
          continue;
        }
        continue;
      }
      d[curu][curv][uu][vv] = d[curu][curv][u][v] + 1;
      qu.push(uu);
      qv.push(vv);
    }
  }
}
int id[22][22];
int main() {
  while (cin >> n >> t) {
    for (int i = (1), _b = (n); i <= _b; i++)
      for (int j = (1), _b = (n); j <= _b; j++) cin >> scientistMap[i][j];
    for (int i = (1), _b = (n); i <= _b; i++)
      for (int j = (1), _b = (n); j <= _b; j++) cin >> locationMap[i][j];
    memset(d, -1, sizeof d);
    for (int i = (1), _b = (n); i <= _b; i++)
      for (int j = (1), _b = (n); j <= _b; j++)
        if (locationMap[i][j] == 'Z') {
          startx = i;
          starty = j;
          bfs(0, i, j);
        }
    int cur = 0;
    for (int i = (1), _b = (n); i <= _b; i++)
      for (int j = (1), _b = (n); j <= _b; j++) id[i][j] = ++cur;
    MaxFlow flow(2 * n * n + 2);
    for (int i = (1), _b = (n); i <= _b; i++)
      for (int j = (1), _b = (n); j <= _b; j++) {
        if (scientistMap[i][j] >= '1' && scientistMap[i][j] <= '9')
          flow.addEdge(0, id[i][j], scientistMap[i][j] - '0');
        if (locationMap[i][j] >= '1' && locationMap[i][j] <= '9')
          flow.addEdge(n * n + id[i][j], 2 * n * n + 1,
                       locationMap[i][j] - '0');
      }
    for (int i = (1), _b = (n); i <= _b; i++)
      for (int j = (1), _b = (n); j <= _b; j++)
        if (scientistMap[i][j] >= '1' && scientistMap[i][j] <= '9') {
          bfs(1, i, j);
          for (int u = (1), _b = (n); u <= _b; u++)
            for (int v = (1), _b = (n); v <= _b; v++)
              if (locationMap[u][v] >= '1' && locationMap[u][v] <= '9')
                if (d[i][j][u][v] >= 0 && d[i][j][u][v] <= t) {
                  flow.addEdge(
                      id[i][j], n * n + id[u][v],
                      min(locationMap[u][v] - '0', scientistMap[i][j] - '0'));
                }
        }
    cout << flow.getMaxFlow(0, 2 * n * n + 1) << endl;
  }
  return 0;
}
