import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class D {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int n = ni(), m = ni(), nt = ni();
		char[][] map = nm(n,m);
		int[][] portal = new int[n][m];
		for(int i = 0;i < n;i++)Arrays.fill(portal[i], -1);
		int[][] ts = new int[2*nt][];
		for(int i = 0;i < 2*nt;i++){
			ts[i] = na(2);
			for(int j = 0;j < 2;j++)ts[i][j]--;
			portal[ts[i][0]][ts[i][1]] = i;
		}
		int[] dr = { 1, 0, -1, 0 };
		int[] dc = { 0, 1, 0, -1 };
		double[][] M = new double[n*m][n*m];
		for(int i = 0;i < n;i++){
			for(int j = 0;j < m;j++){
				if(map[i][j] != '#' && map[i][j] != '*' && map[i][j] != '%'){
					int cango = 0;
					for(int k = 0;k < 4;k++){
						int ni = i + dr[k], nj = j + dc[k];
						if(ni >= 0 && ni < n && nj >= 0 && nj < m){
							if(map[ni][nj] != '#'){
								cango++;
								if(portal[ni][nj] >= 0){
									int to = portal[ni][nj]^1;
									M[ts[to][0]*m+ts[to][1]][i*m+j] += 1;
								}else{
									M[ni*m+nj][i*m+j] += 1;
								}
							}
						}
					}
					if(cango == 0){
						M[i*m+j][i*m+j] += 1;
					}else{
						for(int k = 0;k < n*m;k++){
							M[k][i*m+j] /= cango;
						}
					}
				}else{
					M[i*m+j][i*m+j] += 1;
				}
			}
		}
		int sr = -1, sc = -1;
		for(int i = 0;i < n;i++){
			for(int j = 0;j < m;j++){
				if(map[i][j] == 'A'){
					sr = i; sc = j;
				}
			}
		}
		double[] v = new double[n*m];
		v[sr*m+sc] = 1;
		double[] inf = INF(M, v);
		double ret = 0;
		double all = 0;
		for(int i = 0;i < n;i++){
			for(int j = 0;j < m;j++){
				all += inf[i*m+j];
				if(map[i][j] == '%'){
					ret += inf[i*m+j];
				}
			}
		}
		
		out.printf("%.14f\n", ret/all);
	}
	
	public static double[] INF(double[][] T, double[] v)
	{
		int n = T.length;
		for(int rep = 0;rep < 400;rep++){
			double[][] U = p2(T);
			double norm = 0;
			for(int i = 0;i < n;i++){
				for(int j = 0;j < n;j++){
					double d = T[i][j]-U[i][j];
					norm += d*d;
				}
			}
			if(norm < 1e-11)break;
//			if(norm == 0)break;
			T = U;
		}
		return mul(T, v);
	}
	
	public static double[] mul(double[][] A, double[] v)
	{
		int m = A.length;
		int n = v.length;
		double[] w = new double[m];
		for(int i = 0;i < m;i++){
			double sum = 0;
			for(int k = 0;k < n;k++){
				sum += A[i][k] * v[k];
			}
			w[i] = sum;
		}
		return w;
	}
	
	public static double[][] p2(double[][] A)
	{
		int n = A.length;
		double[][] C = new double[n][n];
		for(int i = 0;i < n;i++){
			for(int k = 0;k < n;k++){
				for(int j = 0;j < n;j++){
					C[i][j] += A[i][k] * A[k][j];
				}
			}
		}
		return C;
	}

	
	void run() throws Exception
	{
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
	}
	
	public static void main(String[] args) throws Exception { new D().run(); }
	
	private byte[] inbuf = new byte[1024];
	public int lenbuf = 0, ptrbuf = 0;
	
	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }
	
	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	private char[][] nm(int n, int m)
	{
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private int ni()
	{
		int num = 0, b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }
}