fun main(args: Array<String>) {
    val (h, w) = readLine()!!.split(" ").map(String::toInt)
    val grid = Array(h) { readLine()!! }

    for (x in 0 until w) {
        for (y in 0 until h) {
            val left = x - 1
            val right = x + 1
            val up = y - 1
            val down = y + 1

            if (grid[y][x] != '#') {
                continue
            }

            if (0 <= left) {
                if (grid[y][left] == '#') {
                    continue
                }
            }
            if (right < h) {
                if (grid[y][right] == '#') {
                    continue
                }
            }

            if (0 <= up) {
                if (grid[up][x] == '#') {
                    continue
                }
            }

            if (down < w) {
                if (grid[down][x] == '#') {
                    continue
                }
            }

            println("No")
            return
        }
    }
    println("Yes")

}