def matmul(A,B): # A,B: 行列
    res = [[0.0]*len(B[0]) for _ in range(len(A))]
    for i, resi in enumerate(res):
        for k, aik in enumerate(A[i]):
            for j,bkj in enumerate(B[k]):
                resi[j] += aik*bkj
    return res

def matpow(A,p): #A^p mod M
    if p%2:
        return matmul(A, matpow(A,p-1))
    elif p > 0:
        b = matpow(A,p//2)
        return matmul(b,b)
    else:
        return [[int(i==j)*1.0 for j in range(len(A))] for i in range(len(A))]

h,w,t = map(int,input().split())
sx,sy = map(int,input().split())
gx,gy = map(int,input().split())
b = [input() for _ in range(h)]
N = h*w
A = [[0.0]*N for _ in range(N)]
for i in range(1,h-1):
    for j in range(1,w-1):
        if b[i][j] == "#": continue
        v = i*w+j
        c = 0
        for ni,nj in [(i-1,j),(i+1,j),(i,j-1),(i,j+1)]:
            if b[ni][nj] == ".":
                c += 1
        if c==0:
            b[v][v] = 1.0
            continue
        for ni,nj in [(i-1,j),(i+1,j),(i,j-1),(i,j+1)]:
            if b[ni][nj] == ".":
                A[v][ni*w+nj] = 1/c

B = matpow(A,t)
v = [0.0]*N
v[sx*w+sy] = 1.0
v = matmul([v],B)
print(v[0][gx*w+gy])