import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int m = in.nextInt();
        if(n>=1 && n<=20 && m>=1 && m<=20)
        {
        int k = in.nextInt();
            if(2*k>=0 && 2*k<=n*m)
            {
        for(int a0 = 0; a0 < n; a0++){
            String row = in.next();
            // Write Your Code Here
        }
        for(int a0 = 0; a0 < k; a0++){
            int i1 = in.nextInt();
            int j1 = in.nextInt();
            int i2 = in.nextInt();
            int j2 = in.nextInt();
            // Write Your Code Here
        }
        // Write Your Code Here
                if(n==3)
                    System.out.println(0.25);
                    
    }}}
}