#include <bits/stdc++.h>
 
using namespace std;
 
#define int long long
#define PII pair<int,int>
const int INF=1e9+7;
const int N = 3005;
 
int n,m,k;
string s[N];
int a[N][N];
int dis[N][N];
int xx[4]={-1,0,1,0},yy[4]={0,1,0,-1};
 
void bfs(int sx,int sy){
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			dis[i][j]=INF;
		}
	}
	dis[sx][sy]=0;
	queue<PII>q;
	q.push({sx,sy});
	while(!q.empty()){
		int x=q.front().first,y=q.front().second;
		q.pop();
		for(int i=0;i<4;i++){
			int tx=x+xx[i],ty=y+yy[i];
			if(tx>n||tx<1||ty>m||ty<1||s[tx][ty]=='#')continue;
			int w=dis[x][y];
			int lv=max(a[tx][ty]-dis[x][y],0ll);
			if(dis[tx][ty]>w+lv+1){
				dis[tx][ty]=w+lv+1;
				q.push({tx,ty});
			}
		}
	}
}
void solve() {
	cin>>n>>m>>k;
	int sx,sy;
	for(int i=1;i<=k;i++){
		int x,y;cin>>x>>y;
		a[x][y]=k-i;
		if(i==1)sx=x,sy=y;
	}
	for(int i=1;i<=n;i++){
		cin>>s[i];
		s[i]=' '+s[i];
	}
	bfs(sx,sy);
//	for(int i=1;i<=n;i++){
//		for(int j=1;j<=m;j++){
//			if(dis[i][j]==INF)cout<<"x ";
//			else cout<<dis[i][j]<<' ';
//		}
//		cout<<'\n';
//	}
//	cout<<'\n';
	unsigned long long ans=0;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			if(dis[i][j]==INF)continue;
			ans+=(unsigned long long)dis[i][j]*dis[i][j];
		}
	}
	cout<<ans<<'\n';
} 
 
signed main() {
	int t=1; //cin >> t;
	while (t--) solve();
	return 0;
}

answer.code:2:1: error: extended character   is not valid in an identifier
    2 |  
      | ^
answer.code:4:1: error: extended character   is not valid in an identifier
    4 |  
      | ^
answer.code:9:1: error: extended character   is not valid in an identifier
    9 |  
      | ^
answer.code:15:1: error: extended character   is not valid in an identifier
   15 |  
      | ^
answer.code:70:1: error: extended character   is not valid in an identifier
   70 |  
      | ^
answer.code:2:1: error: ‘ ’ does not name a type
    2 |  
      | ^
answer.code:4:1: error: ‘ ’ does not name a type
    4 |  
      | ^
answer.code:9:1: error: ‘ ’ does not name a type
    9 |  
      | ^
answer.code:11:1: error: ‘string’ does not name a type; did you mean ‘stdin’?
   11 | string s[N];
      | ^~~~~~
      | stdin
answer.code:15:1: error: ‘ ’ does not name a type
   15 |  
      | ^
answer.code: In function ‘void solve()’:
answer.code:41:9: error: ‘cin’ was not declared in this scope; did you mean ‘std::cin’?
   41 |         cin>>n>>m>>k;
      |         ^~~
      |         std::cin
In file included from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:146,
                 from answer.code:1:
/usr/include/c++/13/iostream:62:18: note: ‘std::cin’ declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
answer.code:41:14: error: ‘n’ was not declared in this scope
   41 |         cin>>n>>m>>k;
      |              ^
answer.code:41:17: error: ‘m’ was not declared in this scope; did you mean ‘tm’?
   41 |         cin>>n>>m>>k;
      |                 ^
      |                 tm
answer.code:41:20: error: ‘k’ was not declared in this scope
   41 |         cin>>n>>m>>k;
      |                    ^
answer.code:49:22: error: ‘s’ was not declared in this scope
   49 |                 cin>>s[i];
      |                      ^
answer.code:52:9: error: ‘bfs’ was not declared in this scope; did you mean ‘ffs’?
   52 |         bfs(sx,sy);
      |         ^~~
      |         ffs
answer.code:64:39: error: ‘INF’ was not declared in this scope
   64 |                         if(dis[i][j]==INF)continue;
      |                                       ^~~
answer.code:68:9: error: ‘cout’ was not declared in this scope; did you mean ‘std::cout’?
   68 |         cout<<ans<<'\n';
      |         ^~~~
      |         std::cout
/usr/include/c++/13/iostream:63:18: note: ‘std::cout’ declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
answer.code: At global scope:
answer.code:70:1: error: ‘ ’ does not name a type
   70 |  
      | ^