#include<bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int, int>
#define fi first
#define se second
#define uint unsigned long long
int read() {
  int res = 0, flg = 1;
  char c = getchar();
  while(!isdigit(c)) {
    if(c == '-') flg = 0;
    c = getchar();
  }
  while(isdigit(c)) {
    res = (res << 3) + (res << 1) + (c ^ 48);
    c = getchar();
  }
  return flg ? res : -res;
}
const int N = 3e3 + 10;
struct Node{
  int x, y, d;
  bool operator < (const Node& other) const{
    return d > other.d;
  }
};
priority_queue<Node> q;
int n, m, k; 
int f[N][N], vis[N][N];
char ma[N][N];
int nxt[5] = {0, 1, 0, -1, 0};
signed main() {
  memset(f, 0x3f, sizeof f);
  memset(ma, '#', sizeof ma);
  n = read(), m = read(), k = read();
  
  
  int x, y, d;
  x = read(), y = read();
  f[x][y] = 0;
  q.push({x, y, 0});
  for(int i = k - 1; i; --i) {
    x = read(), y = read();
    vis[x][y] = i;
  }
  
  for(int i = 1; i <= n; ++i) {
    scanf("%s", ma[i] + 1);
  }
  
  while(q.size()) {
    Node cur = q.top();
    q.pop();
    x = cur.x, y = cur.y;
    d = cur.d;
    
    for(int i = 0; i < 4; ++i) {
      int xx = x + nxt[i], yy = y + nxt[i + 1];
      if(ma[xx][yy] == '#') continue;
      int dd = max(d + 1, vis[xx][yy]);
      if(dd < f[xx][yy]) {
        f[xx][yy] = dd;
        q.push({xx, yy, dd});
      }
    }
  }
  
  uint res = 0;
  for(int i = 1; i <= n; i++) {
    for(int j = 1; j <= m; j++) {
      if(vis[i][j] == -1 || f[i][j] > k * n * n) continue;
      res += f[i][j] * f[i][j];
    }
  }
  cout << res << '\n'; 
  return 0;
}