#include <bits/stdc++.h>
#define N 3006
#define K 1000006

const int dx[] = {0, 0, 1, -1};
const int dy[] = {1, -1, 0, 0};
int n, m, k;
std::vector<std::pair<int, int> > wait[K];
int added[K];
char s[N][N];
int f[N][N], min[N][N];

void bfs(int x, int y) {
	static std::pair<int, int> que[N * N];
	static int left, right;
	std::memset(f, -1, sizeof f);
	left = 1;
	right = 0;
	que[++right] = std::make_pair(x, y);
	f[x][y] = 0;
	while (left <= right) {
		x = que[left].first;
		y = que[left].second;
		left++;
		if (f[x][y] <= k + 1 && !added[f[x][y] + 1]) {
			added[f[x][y] + 1] = 1;
			for (std::pair<int, int> o : wait[f[x][y] + 1]) {
				que[++right] = o;
			}
		}
		for (int _x, _y, k = 0; k < 4; k++) {
			_x = x + dx[k];
			_y = y + dy[k];
			if (_x < 1 || _x > n || _y < 1 || _y > m)
				continue;
			if (s[_x][_y] == '#')
				continue;
			if (f[_x][_y] != -1)
				continue;
			if (min[_x][_y] > f[x][y] + 1) {
				f[_x][_y] = min[_x][_y];
				wait[f[_x][_y]].push_back(std::make_pair(_x, _y));
			} else {
				f[_x][_y] = f[x][y] + 1;
				que[++right] = std::make_pair(_x, _y);
			}
		}
	}
}

int main() {
	scanf("%d%d%d", &n, &m, &k);
	int x, y;
	scanf("%d%d", &x, &y);
	for (int i = k - 1, x, y; i; i--) {
		scanf("%d%d", &x, &y);
		min[x][y] = i;
	}
	for (int i = 1; i <= n; i++)
		scanf("%s", s[i] + 1);
	bfs(x, y);
	unsigned long long ans = 0;
	for (int i = 1; i <= n; i++)
		for (int j = 1; j <= m; j++) {
			if (f[i][j] == -1)
				f[i][j] = 0;
			ans += (unsigned long long)f[i][j] * f[i][j];
		}
	printf("%llu", ans);
	return 0;
}