#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int nax = 107;
int n, m;
char wcz[nax][nax];
int oj[nax];
int fin(int v) {
  if (oj[v] != v) oj[v] = fin(oj[v]);
  return oj[v];
}
void uni(int v, int u) { oj[fin(v)] = fin(u); }
int main() {
  scanf("%d%d", &n, &m);
  for (int i = 1; i <= n; i++) scanf("%s", wcz[i] + 1);
  for (int i = 1; i <= n + m; i++) oj[i] = i;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      if (wcz[i][j] == '#') uni(i, n + j);
    }
  }
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= m; j++) {
      if (wcz[i][j] == '.' && fin(i) == fin(n + j)) {
        printf("No\n");
        return 0;
      }
    }
  }
  printf("Yes\n");
  return 0;
}
