using System;
using System.IO;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;

namespace No659
{
    public class Program
    {
        void Solve(StreamScanner ss, StreamWriter sw)
        {
            //---------------------------------
            var H = ss.Next(Int);
            var W = ss.Next(Int);
            var T = ss.Next(Int);

            var Sy = ss.Next(Int);
            var Sx = ss.Next(Int);
            var Gy = ss.Next(Int);
            var Gx = ss.Next(Int);

            var B = ss.Next(String, H);

            Func<int, int, bool> isInside = (x, y) => 0 <= x && x < W && 0 <= y && y < H;
            int[] dx = { 0, 1, 0, -1 };
            int[] dy = { 1, 0, -1, 0 };
            var dl = 4;
            var random = new Random();

            var walkEnd = (T - 100) % 100 + 100;

            Func<int, int, int, bool> dfs = null;
            dfs = (x, y, t) =>
            {
                if (t == walkEnd) return x == Gx && y == Gy;

                var xs = new List<int>();
                var ys = new List<int>();

                for (var i = 0; i < dl; i++)
                {
                    var cx = x + dx[i];
                    var cy = y + dy[i];

                    if (isInside(cx, cy) && B[cy][cx] == '.')
                    {
                        xs.Add(cx);
                        ys.Add(cy);
                    }
                }

                var r = random.Next(xs.Count);
                var nx = xs[r];
                var ny = ys[r];
                return dfs(nx, ny, t + 1);
            };

            var goalCount = 0;
            var trialCount = 100000d;

            for (var i = 0; i < trialCount; i++)
            {
                if (dfs(Sx, Sy, 0)) goalCount++;
            }

            sw.WriteLine(goalCount / trialCount);
            //---------------------------------
        }

        static void Main()
        {
            var ss = new StreamScanner(new StreamReader(Console.OpenStandardInput()));
            var sw = new StreamWriter(Console.OpenStandardOutput()) {AutoFlush = false};
            new Program().Solve(ss, sw);
            sw.Flush();
        }

        static readonly Func<string, string> String = s => s;
        static readonly Func<string, int> Int = int.Parse;
        static readonly Func<string, long> Long = long.Parse;
        static readonly Func<string, double> Double = double.Parse;
    }

    public class StreamScanner
    {
        static readonly char[] Sep = {' '};
        readonly Queue<string> buffer = new Queue<string>();
        readonly TextReader textReader;

        public StreamScanner(TextReader textReader)
        {
            this.textReader = textReader;
        }

        [SuppressMessage("ReSharper", "PossibleNullReferenceException")]
        public T Next<T>(Func<string, T> parser)
        {
            if (buffer.Count != 0) return parser(buffer.Dequeue());
            var nextStrings = textReader.ReadLine().Split(Sep, StringSplitOptions.RemoveEmptyEntries);
            foreach (var nextString in nextStrings) buffer.Enqueue(nextString);
            return Next(parser);
        }

        public T[] Next<T>(Func<string, T> parser, int x)
        {
            var ret = new T[x];
            for (var i = 0; i < x; ++i) ret[i] = Next(parser);
            return ret;
        }

        public T[][] Next<T>(Func<string, T> parser, int x, int y)
        {
            var ret = new T[y][];
            for (var i = 0; i < y; ++i) ret[i] = Next(parser, x);
            return ret;
        }
    }
}