#include <bits/stdc++.h>
int main() {
  int h, w;
  char color[52][52];
  scanf("%d %d", &h, &w);
  for (int i = 0; i < h + 2; i++) {
    for (int j = 0; j < w + 2; i++) {
      if (i == 0 || j == 0 || i == h + 1 || j == w + 1) {
        color[i][j] = '.';
      } else {
        scanf("%c", &color[i][j]);
      }
      if (i > 1 && j != 0 && j != w + 1 && color[i][j] == '.' &&
          color[i - 1][j] == '#' && color[i - 2][j] == '.' &&
          color[i - 1][j - 1] == '.' && color[i - 1][j + 1] == '.') {
        printf("No");
        return 0;
      }
    }
  }
  printf("Yes");
  return 0;
}
