import numpy as np
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)


def main():
    dydx4 = ((0, 1), (1, 0), (-1, 0), (0, -1))
    h, w, t = map(int, input().split())
    sx, sy = map(int, input().split())
    gx, gy = map(int, input().split())
    S = [input() for _ in range(h)]
    d = abs(sx-gx)+abs(sy-gy)
    if (t-d) % 2 == 1 or d > t:
        return 0.0

    blank = []
    for x in range(h):
        for y in range(w):
            if S[x][y] == ".":
                blank.append(x*w+y)
    n = len(blank)
    btoi = {b: i for i, b in enumerate(blank)}
    A = [0] * (n+1)
    G = [[0]*(n+1) for _ in range(n+1)]
    A[btoi[sx*w+sy]] = 1.0
    A[n] = 1.0
    for i in range(n+1):
        G[i][n] = 1.
    for x in range(h):
        for y in range(w):
            if S[x][y] == ".":
                i = btoi[x*w+y]
                p = 0
                for dx, dy in dydx4:
                    nx = x+dx
                    ny = y+dy
                    p += int(S[nx][ny] == ".")
                if p == 0:
                    G[i][n] = 0
                    G[i][i] = 1.0
                    continue
                for dx, dy in dydx4:
                    nx = x+dx
                    ny = y+dy
                    if 0 <= nx < h and 0 <= ny < w and S[nx][ny] == ".":
                        j = btoi[nx*w+ny]
                        G[j][i] = 1./p
    GG = np.linalg.matrix_power(G, t).tolist()
    res = 0.
    goal = btoi[gx*w+gy]
    for i in range(n):
        res += GG[goal][i] * A[i]
    return res


print("{:.18f}".format(main()))