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#!/usr/bin/env python3
# -*- coding: utf-8 -*-

class CDisjointSet(object):
    def __init__(self):
        self.leader = {} # maps a member to the group's leader
        self.group = {} # maps a group leader to the group (which is a set)
    def Add(self, a, b):
        leadera = self.leader.get(a)
        leaderb = self.leader.get(b)
        if leadera is not None:
            if leaderb is not None:
                if leadera == leaderb: return # nothing to do
                groupa = self.group[leadera]
                groupb = self.group[leaderb]
                if len(groupa) < len(groupb):
                    a, leadera, groupa, b, leaderb, groupb = b, leaderb, groupb, a, leadera, groupa
                groupa |= groupb
                del self.group[leaderb]
                for k in groupb:
                    self.leader[k] = leadera
            else:
                self.group[leadera].add(b)
                self.leader[b] = leadera
        else:
            if leaderb is not None:
                self.group[leaderb].add(a)
                self.leader[a] = leaderb
            else:
                self.leader[a] = self.leader[b] = a
                self.group[a] = set([a, b])

def Judge():
    #[1]
    ds = CDisjointSet()
    n, m = map(int, input().split())
    arr = list()
    for i in range(n):
        arr.append(input())
    for i in range(n):
        for j in range(m):
            if arr[i][j] == '#':
                ds.Add(i+1, 101+j)
    #[2]
    for vs in ds.group.values():
        rs = list()
        cs = list()
        for v in vs:
            if v < 100:
                rs.append(v-1)
            else:
                cs.append(v-101)
        for i in rs:
            for j in range(m):
                if j in cs and arr[i][j] == '.':
                    return False
                if j not in cs and arr[i][j] == '#':
                    return False
    #[3]
    return True

print('Yes') if Judge() else print('No')
