#include <bits/stdc++.h>
using namespace std;
const long long inf = (long long)1e18;
const long long mod = (long long)1e9 + 7;
const double eps = (double)1e-9;
const double pi = acos(-1.0);
const int dx[] = {0, 0, 1, 0, -1};
const int dy[] = {0, 1, 0, -1, 0};
const int N = 55;
int n, m;
char c[N][N];
bool urow[N], ucol[N];
bool rows[N], cols[N];
vector<int> grow[N], gcol[N];
void dfs(int v, bool b) {
  if (!b) {
    urow[v] = 1;
    rows[v] = 1;
    for (auto to : grow[v])
      if (!ucol[to]) dfs(to, 1);
  } else {
    ucol[v] = 1;
    cols[v] = 1;
    for (auto to : gcol[v])
      if (!urow[to]) dfs(to, 0);
  }
}
int main() {
  cin >> n >> m;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      cin >> c[i][j];
      if (c[i][j] == '#') {
        grow[i].push_back(j);
        gcol[j].push_back(i);
      }
    }
  }
  while (1) {
    int ind = -1;
    bool found = 0;
    for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= m; j++) {
        if (c[i][j] == '#' && !urow[i]) {
          ind = i;
          found = 1;
          break;
        }
      }
      if (found) break;
    }
    if (!found) break;
    memset(rows, 0, sizeof(rows));
    memset(cols, 0, sizeof(cols));
    dfs(ind, 0);
    for (int i = 1; i <= n; i++) {
      if (!rows[i]) continue;
      for (int j = 1; j <= m; j++) {
        if (cols[j]) {
          if (c[i][j] == '.') {
            cout << "No";
            return 0;
          }
          c[i][j] = '.';
        }
      }
    }
  }
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      if (c[i][j] == '#') {
        cout << "No";
        return 0;
      }
    }
  }
  cout << "Yes";
  return 0;
}
