#include <bits/stdc++.h>
using namespace std;
bool row[52], col[52];
bool visited[52][52];
int32_t main() {
  long long int n, m;
  scanf("%lld", &n);
  scanf("%lld", &m);
  string s[n + 2];
  for (long long int i = 0; i < n; ++i) {
    cin >> s[i];
  }
  for (long long int i = 0; i < n; ++i) {
    set<long long int> rows, cols;
    if (row[i] == false) {
      for (long long int j = 0; j < m; ++j) {
        if (col[j] == false) {
          if (s[i][j] == '#') {
            rows.insert(i);
            cols.insert(j);
            for (long long int k = i + 1; k < n; ++k) {
              if (s[k][j] == '#') {
                rows.insert(k);
              }
            }
          }
        }
      }
    }
    for (auto l = rows.begin(); l != rows.end(); ++l) {
      if (row[*l] == true) {
        printf("No");
        return 0;
      }
    }
    for (auto l = cols.begin(); l != cols.end(); ++l) {
      if (col[*l] == true) {
        printf("No");
        return 0;
      }
    }
    for (auto l = rows.begin(); l != rows.end(); ++l) {
      row[*l] = true;
      for (auto k = cols.begin(); k != cols.end(); ++k) {
        if (s[*l][*k] == '.') {
          printf("No");
          return 0;
        }
        col[*k] = true;
        visited[*l][*k] = true;
      }
    }
  }
  for (long long int i = 0; i < n; ++i) {
    for (long long int j = 0; j < m; ++j) {
      if (s[i][j] == '#') {
        if (visited[i][j] == false) {
          printf("No");
          return 0;
        }
      }
    }
  }
  printf("Yes");
  return 0;
}
