using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Numerics;
#if DEBUG
using Microsoft.VisualStudio.TestTools.UnitTesting;
#endif
namespace competitive_programming
{
public class Program
{
static void Main(string[] args)
{
#if DEBUG
var scanner = new IO.StreamScanner(File.Open("input.txt", FileMode.Open));
#else
var scanner = new IO.StreamScanner(Console.OpenStandardInput());
#endif
var h = scanner.Integer();
var w = scanner.Integer();
var map = new List<string>();
for (int i = 0; i < h; i++) map.Add(scanner.ScanLine());
var curMap = Enumerable.Range(0, h).Select(v => Enumerable.Range(0, w).Select(u => '.').ToArray()).ToArray();
var dirs_v = new int[] { 1, -1, 0, 0 };
var dirs_w = new int[] { 0, 0, 1, -1 };
for (int i = 0; i < h; i++)
{
for (int j = 0; j < w; j++)
{
if (map[i][j] == '.') continue;
for (int k = 0; k < 4; k++)
{
var ii = i + dirs_v[k];
var jj = j + dirs_w[k];
if (ii < 0 || ii >= h || jj < 0 || jj >= w) continue;
if (map[ii][jj] == '.') continue;
curMap[i][j] = '#';
curMap[ii][jj] = '#';
}
}
}
IO.Printer.Out.WriteLine(Enumerable.Range(0, h).All(i => map[i] == new string(curMap[i])) ? "Yes" : "No");
IO.Printer.Out.Flush();
}
}
}
#if DEBUG
#endif
#region INOUT
namespace IO
{
using System.IO;
using System.Text;
using System.Globalization;
public class Printer : StreamWriter
{
static Printer()
{
Out = new Printer(Console.OpenStandardOutput()) { AutoFlush = false };
}
public static Printer Out { get; set; }
public override IFormatProvider FormatProvider
{
get { return CultureInfo.InvariantCulture; }
}
public Printer(Stream stream)
: base(stream, new UTF8Encoding(false, true))
{
}
public Printer(Stream stream, Encoding encoding)
: base(stream, encoding)
{
}
public void Write<T>(string format, T[] source)
{
base.Write(format, source.OfType<object>().ToArray());
}
public void WriteLine<T>(string format, T[] source)
{
base.WriteLine(format, source.OfType<object>().ToArray());
}
}
public class StreamScanner
{
public StreamScanner(Stream stream)
{
str = stream;
}
public readonly Stream str;
private readonly byte[] buf = new byte[1024];
private int len, ptr;
public bool isEof;
public bool IsEndOfStream
{
get { return isEof; }
}
private byte read()
{
if (isEof) return 0;
if (ptr < len) return buf[ptr++];
ptr = 0;
if ((len = str.Read(buf, 0, 1024)) > 0) return buf[ptr++];
isEof = true;
return 0;
}
public char Char()
{
byte b;
do b = read(); while ((b < 33 || 126 < b) && !isEof);
return (char)b;
}
public string Scan()
{
var sb = new StringBuilder();
for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
sb.Append(b);
return sb.ToString();
}
public string ScanLine()
{
var sb = new StringBuilder();
for (var b = Char(); b != '\n'; b = (char)read())
if (b == 0) break;
else if (b != '\r') sb.Append(b);
return sb.ToString();
}
public long Long()
{
if (isEof) return long.MinValue;
long ret = 0;
byte b;
var ng = false;
do b = read(); while (b != 0 && b != '-' && (b < '0' || '9' < b));
if (b == 0) return long.MinValue;
if (b == '-')
{
ng = true;
b = read();
}
for (; ; b = read())
{
if (b < '0' || '9' < b)
return ng ? -ret : ret;
ret = ret * 10 + b - '0';
}
}
public int Integer()
{
return (isEof) ? int.MinValue : (int)Long();
}
public double Double()
{
var s = Scan();
return s != "" ? double.Parse(s, CultureInfo.InvariantCulture) : double.NaN;
}
static T[] enumerate<T>(int n, Func<T> f)
{
var a = new T[n];
for (int i = 0; i < n; ++i) a[i] = f();
return a;
}
public char[] Char(int n)
{
return enumerate(n, Char);
}
public string[] Scan(int n)
{
return enumerate(n, Scan);
}
public double[] Double(int n)
{
return enumerate(n, Double);
}
public int[] Integer(int n)
{
return enumerate(n, Integer);
}
public long[] Long(int n)
{
return enumerate(n, Long);
}
}
}
#endregion