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

#define Gene template< class
#define Rics printer& operator,
Gene c> struct rge{c b, e;};
Gene c> rge<c> range(c i, c j){ return {i, j};}
struct printer{
    ~printer(){cerr<<endl;}
    Gene c >Rics(c x){ cerr<<boolalpha<<x; return *this;}
    Rics(string x){cerr<<x;return *this;}
    Gene c, class d >Rics(pair<c, d> x){ return *this,"(",x.first,", ",x.second,")";}
    Gene ... d, Gene ...> class c >Rics(c<d...> x){ return *this, range(begin(x), end(x));}
    Gene c >Rics(rge<c> x){
        *this,"["; for(auto it = x.b; it != x.e; ++it)
            *this,(it==x.b?"":", "),*it; return *this,"]";}
};
#define debug() cerr<<"LINE "<<__LINE__<<" >> ", printer()
#define dbg(x) "[",#x,": ",(x),"] "
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int my_rand(int l, int r) {
    return uniform_int_distribution<int>(l, r) (rng);
}


int main() {
//    freopen("in.txt", "r", stdin);
    ios::sync_with_stdio(0);
    cin.tie(0);

    int n, m, k;
    cin >> n >> m >> k;
    vector<string> grid(n);
    for(int i = 0; i < n; i++) cin >> grid[i];
    priority_queue<tuple<int,int,int>> pq;
    vector<vector<int>> dis(n, vector<int>(m, -1));
    for(int i = 0; i < k; i++) {
        int x, y, c;
        cin >> x >> y >> c;
        x--, y--;
        assert(grid[x][y] == '.');
        pq.push(make_tuple(c, x, y));
        dis[x][y] = c;
    }
    vector<int> dx = {0,0,+1,-1};
    vector<int> dy = {+1,-1,0,0};
    int ans = 0;
    while(pq.size() > 0) {
        auto t = pq.top();
        int x = get<1>(t), y = get<2>(t);
        int c = get<0>(t);
        pq.pop();
        if(c == 0) continue;
        for(int k = 0; k < 4; k++) {
            int nx = x+dx[k], ny = y+dy[k];
            if(nx >= 0 && nx < n && ny >= 0 && ny < m && grid[nx][ny] == '.' && dis[nx][ny] < c-1) {
                dis[nx][ny] = c-1;
                pq.push(make_tuple(c-1,nx,ny));
            }
        }
    }
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            ans += dis[i][j] != -1;
        }
    }
    cout << ans << endl;
}