R, C, T = gets.split.map &:to_i
Sy, Sx = gets.split.map &:to_i
Gy, Gx = gets.split.map &:to_i
Board = $<.map{|s|s.chomp.chars}

DIRS = [[1,0],[-1,0],[0,1],[0,-1]]
BITS_COUNT = [
  0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
]
flags = R.times.map{ [0]*C }
(1...R).each{|y|
  (1...C).each{|x|
    next if Board[y][x] == ?#
    flags[y][x] = DIRS.map.with_index{|(dy, dx), i|
      Board[y+dy][x+dx] == ?# ? 0 : 1 << i
    }.inject :|
  }
}

state = R.times.map{ [0.0]*C }
dp = state.map &:dup
dp[Sy][Sx] = 1.0
[T, 10000+T%2].min.times{
  next_dp = state.map &:dup
  (1...R).each{|y|
    (1...C).each{|x|
      next if Board[y][x] == ?#
      dir_count = BITS_COUNT[flags[y][x]]
      if dir_count == 0
        next_dp[y][x] += dp[y][x]
        next
      end
      DIRS.each_with_index{|(dy, dx), d|
        next if flags[y][x] & (1 << d) == 0
        next_dp[y+dy][x+dx] += dp[y][x] / dir_count
      }
    }
  }
  dp = next_dp
}
p dp[Gy][Gx].to_f