#include <bits/stdc++.h>
using namespace std;
const int N = 100;
struct node {
  int x, y;
};
int n, m;
char s[N][N], p[N][N];
set<int> row, col;
void bfs(int x, int y) {
  node a, b;
  a.x = x, a.y = y;
  queue<node> q;
  q.push(a);
  while (!q.empty()) {
    a = q.front();
    row.insert(a.x);
    col.insert(a.y);
    for (int i = 1; i <= n; i++) {
      if (s[i][a.y] == '#' && p[i][a.y] != 1) {
        p[i][a.y] = 1;
        b.x = i;
        b.y = a.y;
        q.push(b);
      }
    }
    for (int i = 1; i <= m; i++) {
      if (s[a.x][i] == '#' && p[a.x][i] != 1) {
        p[a.x][i] = 1;
        b.x = a.x;
        b.y = i;
        q.push(b);
      }
    }
    q.pop();
  }
}
int main() {
  scanf("%d%d", &n, &m);
  for (int i = 0; i < n; i++) {
    scanf("%s", s[i]);
  }
  int f = 1;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      if (s[i][j] == '#' && p[i][j] != 1) {
        row.clear();
        col.clear();
        p[i][j] = 1;
        bfs(i, j);
        for (set<int>::iterator it = row.begin(); it != row.end(); ++it) {
          for (set<int>::iterator po = col.begin(); po != col.end(); ++po) {
            if (s[*it][*po] != '#') f = 0;
          }
        }
      }
    }
  }
  if (f)
    puts("Yes");
  else
    puts("No");
  return 0;
}
