#include <bits/stdc++.h>
using namespace std;
int s[100][100];
int main(void) {
  int w, h;
  int ans;
  scanf("%d%d", &h, &w);
  for (int i = 1; i <= h; i++) {
    char buf[100];
    for (int j = 1; j <= w; j++) {
      s[j][i] = (buf[j - 1] == '#');
    }
  }
  ans = true;
  for (int i = 1; i <= h; i++) {
    for (int j = 1; j <= w; j++) {
      s[j][i] &&
          (ans &= s[j - 1][i] || s[j + 1][i] || s[j][i - 1] || s[j][i + 1]);
    }
  }
  puts(ans ? "Yes" : "No");
  return 0;
}
