#include <bits/stdc++.h>
using namespace std;
const int N = 105;
int n, m;
bool inv[N], czy, inv2[N];
char s[N][N], ans[N][N];
vector<int> v[N];
void dfs(int x) {
  inv[x] = 1;
  inv2[x] = 1;
  for (auto y : v[x])
    if (!inv[y]) dfs(y);
}
int main() {
  scanf("%d%d", &n, &m);
  for (int i = 0; i < n; i++) {
    scanf("%s", &s[i]);
    for (int j = 0; j < m; j++)
      if (s[i][j] == '#') {
        v[i].push_back(j + n);
        v[j + n].push_back(i);
      }
  }
  for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++) ans[i][j] = '.';
  for (int i = 0; i < n + m; i++)
    if (!inv[i]) {
      dfs(i);
      for (int j = 0; j < n; j++)
        for (int k = 0; k < m; k++)
          if (inv2[j] && inv2[k + n]) ans[j][k] = '#';
      for (int j = 0; j < n + m; j++) inv2[j] = 0;
    }
  bool czy = 1;
  for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++)
      if (s[i][j] != ans[i][j]) czy = 0;
  if (czy)
    printf("Yes");
  else
    printf("No");
  return 0;
}
