using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace YukiCoder
{
    class Program
    {
        //------------------------------------------------------------------//
        static bool forXY(string S, int dY, int dX)
        {
            var va = S.Split().Select(a => a.ToCharArray()).ToArray();
            for (int y = 0; y < yMax; y++)
            {
                if (y + dY >= yMax) break;
                for (int x = 0; x < xMax; x++)
                {
                    if (x + dX < 0 || x + dX >= xMax)                   continue;
                    if (va[y][x] != '#')                                continue;
                    if (va[y + dY][x + dX] != '#')                      return false;
                    va[y][x] = va[y + dY][x + dX] = '.';
                }
            }
            for (int y = 0; y < yMax; y++)
            {
                for (int x = 0; x < xMax; x++)
                {
                    if (va[y][x] == '#') return false;
                }
            }
            return true;
        }
        //------------------------------------------------------------------//
        static bool forDxDy(string S)
        {
            for (int dy = 0; dy < yMax; dy++)
            {
                for (int dx = -xMax + 1; dx < xMax; dx++)
                {
                    if (dy == 0 && dx == 0) continue;
                    if (forXY(S, dy, dx)) return true;
                }
            }
            return false;
        }
        //------------------------------------------------------------------//
        static int yMax = 3;
        static int xMax = 3;
        static void Main(string[] args)
        {
            var va = Console.ReadLine().Trim().Split().Select(int.Parse).ToArray();
            yMax = va[0];
            xMax = va[1];
            string[] ps = new string[yMax];

            for (int i = 0; i < yMax; i++)
            {
                ps[i] = Console.ReadLine();
            }
            string S = string.Join(" ", ps);

            if (forDxDy(S)) Console.WriteLine("YES");
            else Console.WriteLine("NO");
            Console.ReadLine();
        }
        //------------------------------------------------------------------//
    }
}