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#include <bits/stdc++.h>
using namespace std;
struct pt {
  int x, y;
  pt() : x(0), y(0) {}
  pt(int _y, int _x) : x(_x), y(_y) {}
  bool operator<(const pt other) const {
    return x < other.x || (x == other.x && y == other.y);
  }
};
int h, w;
vector<vector<char>> field;
set<pt> visited;
map<pt, vector<pt>> g;
vector<vector<bool>> used;
void print(pt p) { cerr << "(y:" << p.y << ", x:" << p.x << ")"; }
void dfs(pt p) {
  if (used[p.y][p.x]) return;
  print(p);
  cerr << endl;
  used[p.y][p.x] = true;
  visited.insert(p);
  for (auto to : g[p]) {
    dfs(to);
  }
}
int main() {
  cin >> h >> w;
  field.resize(h, vector<char>(w));
  for (int y = 0; y < h; ++y) {
    for (int x = 0; x < w; ++x) {
      cin >> field[y][x];
    }
  }
  vector<vector<set<int>>> byy(h, vector<set<int>>(w));
  vector<vector<set<int>>> byx(h, vector<set<int>>(w));
  for (int y = 0; y < h; ++y) {
    for (int x = 0; x < w; ++x) {
      if (field[y][x] == '#') {
        for (int y1 = 0; y1 < h; ++y1) {
          if (field[y1][x] == '#') {
            byy[y][x].insert(y1);
          }
        }
        for (int x1 = 0; x1 < w; ++x1) {
          if (field[y][x1] == '#') {
            byx[y][x].insert(x1);
          }
        }
      }
    }
  }
  for (int y = 0; y < h; ++y) {
    for (int x = 0; x < w; ++x) {
      if (field[y][x] == '#') {
        for (int y1 = 0; y1 < h; ++y1) {
          if (field[y1][x] == '#') {
            if (byx[y][x] != byx[y1][x]) {
              cout << "No" << endl;
              return 0;
            }
          }
        }
        for (int x1 = 0; x1 < w; ++x1) {
          if (field[y][x1] == '#') {
            if (byy[y][x] != byy[y][x1]) {
              cout << "No" << endl;
              return 0;
            }
          }
        }
      }
    }
  }
  cout << "Yes" << endl;
  return 0;
}
