import sys # sys.setrecursionlimit(1000005) # sys.set_int_max_str_digits(200005) int1 = lambda x: int(x)-1 pDB = lambda *x: print(*x, end="\n", file=sys.stderr) p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr) def II(): return int(sys.stdin.readline()) def LI(): return list(map(int, sys.stdin.readline().split())) def LLI(rows_number): return [LI() for _ in range(rows_number)] def LI1(): return list(map(int1, sys.stdin.readline().split())) def LLI1(rows_number): return [LI1() for _ in range(rows_number)] def SI(): return sys.stdin.readline().rstrip() dij = [(0, 1), (-1, 0), (0, -1), (1, 0)] # dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)] # inf = -1-(-1 << 31) inf = -1-(-1 << 62) # md = 10**9+7 md = 998244353 from copy import deepcopy h, w = LI() ss = [[c == "#" for c in SI()] for _ in range(h)] a = deepcopy(ss) for i in range(h): for j in range(w): if i and j and a[i][j]: a[i][j] += a[i-1][j-1] b = deepcopy(ss) for i in range(h): for j in range(w): if i and j+11: k-=1 x[i-k][j-k]+=1 x[i+k+1][i+k+1]-=1 for i in range(h): for j in range(w): x[i+1][j+1]+=x[i][j] y=[[0]*(w+1) for _ in range(h+1)] for i in range(h): for j in range(w): k=min(b[i][j],c[i][j]) if k>1: k-=1 y[i-k][j+k]+=1 y[i+k+1][i-k+1]-=1 for i in range(h): for j in range(w)[::-1]: y[i+1][j-1]+=y[i][j] for i in range(h): for j in range(w): if ss[i][j]==0 and x[i][j]+y[i][j]>0: print("No") exit() if ss[i][j]>0 and x[i][j]+y[i][j]==0: print("No") exit() print("Yes")