#include <bits/stdc++.h>
using namespace std;
int matr[100][100];
int r[100], c[100];
set<int> rows[57];
set<int> cols[57];
int main() {
  int n, m;
  cin >> m >> n;
  getchar();
  for (int i = 0; i < m; i++) {
    for (int j = 0; j < n; j++) {
      matr[i][j] = -1;
    }
  }
  for (int i = 0; i < m; i++) {
    for (int j = 0; j < n; j++) {
      int c = getchar();
      if (c == '#') {
        matr[i][j] = 1;
      } else {
        matr[i][j] = 0;
      }
    }
    getchar();
  }
  for (int i = 0; i < m; i++) {
    for (int j = 0; j < n; j++) {
      if (matr[i][j] == 1) {
        rows[i].insert(j);
        cols[j].insert(i);
      }
    }
  }
  for (int i = 0; i < m; i++) {
    set<int> colsa, rowsa;
    if (r[i] == 1) {
      continue;
    }
    rowsa.insert(i);
    for (int num : rows[i]) {
      colsa.insert(num);
    }
    bool flag = 1;
    while (flag) {
      flag = 0;
      for (int num : colsa) {
        for (int rw : cols[num]) {
          int olds = rowsa.size();
          rowsa.insert(rw);
          if (rowsa.size() != olds) {
            flag = 1;
          }
        }
      }
      for (int num : rowsa) {
        for (int cl : rows[num]) {
          int olds = colsa.size();
          colsa.insert(cl);
          if (colsa.size() != olds) {
            flag = 1;
          }
        }
      }
      for (int n1 : rowsa) {
        for (int n2 : colsa) {
          if (matr[n1][n2] == 0) {
            cout << "No\n";
            return 0;
          }
        }
      }
      for (int n1 : rowsa) {
        if (r[n1]) {
          cout << "No\n";
          return 0;
        }
      }
      for (int n2 : colsa) {
        if (c[n2]) {
          cout << "No\n";
          return 0;
        }
      }
    }
    for (int n1 : rowsa) {
      r[n1] = 1;
    }
    for (int n2 : colsa) {
      c[n2] = 1;
    }
  }
  cout << "Yes\n";
  return 0;
}
