9 5
.....
#....
..#..
.....
.#..#
...#.
.#...
....#
.....
 4 10
..#......#
.....##...
#.........
.#.......#
 50 2
..
..
#.
..
.#
..
..
..
.#
..
..
.#
##
..
..
..
.#
..
..
.#
..
..
.#
..
..
.#
..
.#
..
.#
..
.#
.#
.#
..
..
..
.#
.#
.#
..
..
.#
.#
..
..
..
..
..
..
 2 50
...#.##.###...#.#..##....##..........#.#..#.#####.
...#.##.###...#.#..##....##..........#.#..#.#####.
 1 1
#
 3 3
.##
#.#
##.
 50 8
.....#..
........
........
.....#..
.....#..
........
........
........
........
...#....
...#....
........
...#....
#.#.#...
...#....
...#....
........
...#....
...#....
...#....
........
#.#.#...
.....#..
........
#.#.#...
#.#.#...
#.#.#...
...#....
........
........
........
#.#.#...
........
.....#..
........
........
........
........
........
........
.....#..
........
........
........
.....#..
#.#.#...
...#....
........
........
........
 1 1
.
 25 16
.............#..
.............#..
.......#...#....
............#...
.....#..........
.....#..........
#...............
................
........#.......
................
................
.#..............
#...............
.....#..........
.#..............
............#...
................
................
................
........#.......
..#.............
..........#.....
.......#...#....
.............#..
..........#.....
 25 16
..............#.
................
...#...#........
........#.#.....
..............##
..............#.
.......#........
......#.........
............#...
.........#.....#
..............#.
.......#........
#...........#...
...#.#..........
.#..............
................
......#.....#...
.......#........
........#.....#.
................
......#.........
..#.............
................
...#.#..........
.#..............
 10 15
.......#.......
.....#.........
....#..........
....#..........
.....#.........
.....#.........
#.............#
...#..#........
...............
.............#.
 4 10
###..#..##
...##..#..
.##..#..#.
.........#
 2 5
.####
#..##
 5 2
##
##
..
##
..
 2 2
##
#.
 50 1
.
.
#
.
#
.
#
.
.
#
#
#
.
#
#
#
#
.
.
.
.
.
.
.
.
.
#
#
#
#
.
.
.
.
.
#
.
.
.
#
#
.
.
#
#
.
.
#
#
.
 5 2
#.
##
##
#.
..
 2 3
#.#
###
 2 1
.
#
 2 3
#.#
##.
 10 10
..........
..........
..........
..........
.#.......#
#.........
......#...
..........
..........
#.....#...
 4 4
###.
##.#
#.##
.###

No
 No
 No
 Yes
 Yes
 No
 Yes
 Yes
 Yes
 No
 Yes
 No
 No
 Yes
 No
 Yes
 No
 No
 Yes
 No
 No
 No

#include <bits/stdc++.h>
using namespace std;
bool comp(unsigned long long x, unsigned long long y) { return x > y; }
int dx[] = {0, 0, 1, -1, 1, 1, -1, -1};
int dy[] = {1, -1, 0, 0, -1, 1, 1, -1};
class UnionFind {
 private:
  vector<int> p, rank;

 public:
  UnionFind(int N) {
    rank.assign(N, 0);
    p.assign(N, 0);
    for (int i = 0; i < N; i++) p[i] = i;
  }
  int findSet(int i) { return (p[i] == i) ? i : (p[i] = findSet(p[i])); }
  bool isSameSet(int i, int j) { return findSet(i) == findSet(j); }
  void unionSet(int i, int j) {
    if (!isSameSet(i, j)) {
      int x = findSet(i), y = findSet(j);
      if (rank[x] > rank[y]) {
        p[y] = x;
      } else {
        p[x] = y;
        if (rank[x] == rank[y]) rank[y]++;
      }
    }
  }
};
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
vector<int> getdividors(int n) {
  vector<int> dividors;
  int i;
  for (i = 1; i * i < n; i++) {
    if (n % i == 0) {
      if (i != 1) dividors.push_back(i);
      dividors.push_back(n / i);
    }
  }
  if (i * i == n) dividors.push_back(i);
  return dividors;
}
bool palindrome(string s) {
  int len = s.length();
  for (int i = 0; i < len / 2; i++)
    if (s[i] != s[len - i - 1]) return false;
  return true;
}
long long C(long long n) { return n * (n - 1) / 2; }
void solveA() {
  int a;
  cin >> a;
  cout << a << endl;
}
void solveB() {
  int n, m;
  cin >> n >> m;
  char grid[100][100];
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      cin >> grid[i][j];
    }
  }
  int matched[100][100];
  bool can = true;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (grid[i][j] == '#') {
        for (int k = 0; k < m; k++) {
          if (grid[i][k] == '#') matched[i][k]++;
        }
        for (int k = 0; k < n; k++) {
          if (grid[k][j] == '#') matched[k][j]++;
        }
      }
    }
  }
  for (int i = 0; i < n; i++) {
    bool foundFirst = false;
    int val = -1;
    for (int j = 0; j < m; j++) {
      if (grid[i][j] == '#') {
        if (foundFirst && matched[i][j] != val)
          can = false;
        else if (!foundFirst) {
          foundFirst = true;
          val = matched[i][j];
        }
      }
    }
  }
  for (int j = 0; j < m; j++) {
    bool foundFirst = false;
    int val = -1;
    for (int i = 0; i < n; i++) {
      if (grid[i][j] == '#') {
        if (foundFirst && matched[i][j] != val)
          can = false;
        else if (!foundFirst) {
          foundFirst = true;
          val = matched[i][j];
        }
      }
    }
  }
  if (can)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
vector<int> factorize(long long n) {
  vector<int> factors;
  for (long long i = 2; i * i <= n; i++) {
    while (n % i == 0) factors.push_back(i), n /= i;
  }
  if (n > 1) factors.push_back(n);
  return factors;
}
int main() {
  solveB();
  return 0;
}
