#include <bits/stdc++.h>
using namespace std;
int n, m;
string k[60];
int usedI[60] = {0};
int usedJ[60] = {0};
queue<int> qI, qJ;
int main() {
  cin >> n >> m;
  for (int i = 0; i < n; i++) cin >> k[i];
  bool res = true;
  int cont = 1;
  for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++) {
      cont++;
      if (k[i][j] == '#') {
        if (usedI[i] == 0) {
          qI.push(i);
          usedI[i] = cont;
        }
        if (usedJ[j] == 0) {
          qJ.push(j);
          usedJ[j] = cont;
        }
        while (!qI.empty() || !qJ.empty()) {
          if (!qJ.empty()) {
            int _j = qJ.front();
            qJ.pop();
            for (int ii = 0; ii < n; ii++) {
              if (k[ii][_j] == '#') {
                if (usedI[ii] == 0) {
                  qI.push(ii);
                  usedI[ii] = cont;
                }
              }
            }
          } else {
            int _i = qI.front();
            qI.pop();
            for (int jj = 0; jj < m; jj++) {
              if (k[_i][jj] == '#') {
                if (usedJ[jj] == 0) {
                  qJ.push(jj);
                  usedJ[jj] = cont;
                }
              }
            }
          }
        }
      }
    }
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (usedI[i] != 0 && usedI[i] == usedJ[j] && k[i][j] == '.') res = false;
      if (usedI[i] == 0 && usedJ[j] == 0 && k[i][j] == '#') res = false;
      if (usedI[i] != usedJ[j] && k[i][j] == '#') res = false;
    }
  }
  if (res)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
