#include <bits/stdc++.h>
const int MAXINT = 2147483640;
const long long MAXLL = 9223372036854775800LL;
const long long MAXN = 1000000;
const double eps = 1e-9;
const long long mod = 1e9 + 7;
using namespace std;
long long binpow(long long a, long long n) {
  long long ans = 1;
  while (n) {
    if (n & 1) ans *= a;
    a *= a;
    n >>= 1;
  }
  return ans;
}
long long n, m;
char a[1000][1000];
vector<long long> v[100];
set<long long> s[60], s1[60];
int main() {
  srand(time(0));
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  ;
  cin >> n >> m;
  for (int i = 1; i <= n; ++i) {
    for (int j = 1; j <= m; ++j) {
      cin >> a[i][j];
      if (a[i][j] == '#') {
        v[j].push_back(i);
      }
    }
  }
  vector<long long> vi;
  for (int i = 1; i <= n; ++i) {
    long long f = 0;
    long long ans = 0;
    vi.clear();
    for (int j = 1; j <= m; ++j) {
      if (a[i][j] == '#') {
        vi.push_back(j);
      }
    }
    long long k = vi.size();
    for (int i = 0; i < k - 1; ++i) {
      if (v[vi[i]].size() != v[vi[i + 1]].size()) {
        cout << "No" << endl;
        return 0;
      } else {
        if (v[vi[i]] != v[vi[i + 1]]) {
          cout << "No" << endl;
          return 0;
        }
      }
    }
  }
  cout << "Yes" << endl;
  return 0;
}
