#include <bits/stdc++.h>
using namespace std;

#ifdef LOCAL
#define eprintf(...) fprintf(stderr, __VA_ARGS__)
#define print_var(x) cerr << #x << " = " << x << endl
#define print_array(arr, len) {cerr << #arr << " = "; for (int i = 0; i < len; i++) cerr << arr[i] << " "; cerr << endl;}
#define print_iterable(it) {cerr << #it << " = "; for (const auto &e : it) cerr << e << " "; cerr << endl;}
#else
#define eprintf(...) (void)0
#define print_var(x) (void)0
#define print_array(arr, len) (void)0
#define print_iterable(it) (void)0
#endif

typedef long long ll;

const int DX[] = {1, 0, -1, 0};
const int DY[] = {0, 1, 0, -1};
const int INF = (int)1e8;
const int K = 7;
const int N = 110;
char table[N][N];
int n, m;
int k;
pair<int, int> points[K];
int dist[K][N][N];

bool read()
{
    scanf("%d%d", &n, &m);
    if (n + m == 0)
        return false;
    for (int i = 0; i < n; i++)
        scanf(" %s", table[i]);
    scanf("%d", &k);
    for (int i = 0; i < k; i++)
    {
        scanf("%d%d", &points[i].first, &points[i].second);
        points[i].first--;
        points[i].second--;
    }
    return true;
}

void put_start()
{
    for (int i = 0; i < n; i++)
    {
        for (int s = 0; s < m; s++)
        {
            if (table[i][s] == '@')
                points[k] = make_pair(i, s);
        }
    }
}

pair<int, int> q[N * N];

bool valid_cell(int x, int y)
{
    if (x < 0 || y < 0 || x >= n || y >= m)
        return false;
    return table[x][y] != '@';
}

void calc_dist(pair<int, int> start, int cur_dist[N][N])
{
    for (int i = 0; i < n; i++)
        for (int s = 0; s < m; s++)
            cur_dist[i][s] = INF;
    cur_dist[start.first][start.second] = 0;
    int r = 0;
    q[r++] = start;
    for (int i = 0; i < r; i++)
    {
        auto v = q[i];
        for (int d = 0; d < 4; d++)
        {
            int nx = v.first + DX[d];
            int ny = v.second + DY[d];
            if (valid_cell(nx, ny) && cur_dist[nx][ny] > cur_dist[v.first][v.second] + 1)
            {
                q[r++] = make_pair(nx, ny);
                cur_dist[v.first][v.second] = cur_dist[nx][ny] + 1;
            }
        }
    }
}

void solve()
{
    put_start();
    vector <int> perm = {};
    for (int i = 0; i <= k; i++)
    {
        calc_dist(points[i], dist[i]);
        perm.push_back(i);
    }
    swap(perm[k], perm[0]);
    int ans = INF;
    do
    {
        int loc_ans = 0;
        for (int i = 0; i < k; i++)
        {
            auto next_pos = points[perm[i + 1]];
            loc_ans += dist[perm[i]][next_pos.first][next_pos.second];
        }
        ans = min(ans, loc_ans);
    } while (next_permutation(perm.begin() + 1, perm.end()));
    if (ans == INF)
        puts("-1");
    else
        printf("%d\n", ans);
}

int main()
{
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
#endif

    while (read())
        solve();

    eprintf("\n\ntime = %.3lf\n", (double)clock() / CLOCKS_PER_SEC);
}