/*
	"Why do we fall? So we can learn how to pick ourselves up."
	- Alfred, Batman Begins -
*/

# include <iostream>
# include <cstdio>
# include <algorithm>
# include <cmath>
# include <set>
# include <cstring>
# include <string.h>
# include <sstream>
# include <map>
# include <queue>
# include <vector>

# define mp make_pair
# define LL long long
# define vi vector<int>
# define pqu priority_queue
# define iasc int,vector<int>,greater<int>
# define LLasc  LL,vector<LL>,greater<LL>
# define ins push_back
# define pii pair<int,int>
# define fi first
# define se second

inline void in(int &MAGNUS) {scanf("%d",&MAGNUS);}
inline void out(int MAGNUS) {printf("%d\n",MAGNUS);}
inline void in(int &MAGNUS,int &CLAR) {scanf("%d%d",&MAGNUS,&CLAR);}
inline void out(int MAGNUS,int CLAR) {printf("%d %d\n",MAGNUS,CLAR);}

inline void inl(LL &LIV) {scanf("%lld",&LIV);}
inline void inl(LL &LIV,LL &MART) {scanf("%lld%lld",&LIV,&MART);}
inline void outl(LL LIV) {printf("%lld\n",LIV);}
inline void outl(LL LIV, LL MART) {printf("%lld %lld\n",LIV,MART);}

# define FORU(a,b,c) for(int a=b; a<=c; a++)
# define FORD(a,b,c) for(int a=b; a>=c; a--)
# define FOR(a,b) for(int a=1; a<=b; a++)
# define FORA(a,b) for(auto (a) : (b))
# define REP(a,b) for(int a=0; a<b; a++)
# define RESET(a) memset(a,0,sizeof(a))
# define MEMO(a) memset(a,-1,sizeof(a))
# define ALL(a) (a).begin(),(a).end()
# define RNG(a,b) (a)+1,(a)+(b)+1
# define BSL(a,b) lower_bound(ALL(a),(b))-(a).begin()
# define BSLX(a,b,c) lower_bound((a)+1,(a)+(b)+1,(c))-a
# define BSU(a,b) upper_bound(ALL(a),(b))-(a).begin()
# define BSUX(a,b,c) upper_bound((a)+1,(a)+(b)+1,(c))-a
# define DEBUG puts("this-part-has-been-reach")

using namespace std;

int R,C,K,sr,sc;
bool tunnel[55][55];
pii warp[55][55];
char m[55][55];

int dx[]={-1,0,1,0};
int dy[]={0,-1,0,1};
bool vis[55][55];

bool inside(int r,int c){
	return 1<=r && r<=R && 1<=c && c<=C;	
}

bool loop(int r,int c){
	FORU(i,0,3){
		int nxr=r+dx[i], nxc=c+dy[i];
		if(!inside(nxr,nxc)) continue;
		if(tunnel[nxr][nxc]) continue;
		if(m[nxr][nxc]!='O') continue;
		return 1;
	}
	return 0;
}

int main(){
	
	in(R,C); in(K);
	FOR(i,R) FOR(j,C){
		cin >> m[i][j];
		if(m[i][j]=='A') sr=i, sc=j;	
	}
	
	FOR(k,K){
		int r1,c1,r2,c2;
		in(r1,c1); in(r2,c2);
		tunnel[r1][c1]=tunnel[r2][c2]=1;
		if(loop(r1,c1) || loop(r2,c2)){
			printf("%.6lf\n",0);
			return 0;
		}
		warp[r1][c1]=mp(r2,c2);
		warp[r2][c2]=mp(r1,c1);
	}
	
	int bom=0, done=0, trap=0;
	queue<pii> q;
	q.push(mp(sr,sc));
	while(!q.empty()){
		pii state=q.front();
		q.pop();
		
		int r=state.fi, c=state.se;
		vis[r][c]=1;	
		
		int allwall=1;
		FORU(i,0,3){
			int nxr=r+dx[i];
			int nxc=c+dy[i];
			if(!inside(nxr,nxc)) continue;
			if(m[nxr][nxc]=='%') allwall=0,done++;
			else if(m[nxr][nxc]=='*') allwall=0,bom++;
			else if(m[nxr][nxc]=='O'){
				pii nex=warp[nxr][nxc];
				allwall=0;
				if(vis[nex.fi][nex.se]) continue;
				q.push(nex);
			}
		}
		if(allwall) trap++;
	}
	
	printf("%.6lf\n",done/(double)(done+bom+trap));

	return 0;
}