#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<ll, ll>;
constexpr ll MOD = 998244353;
constexpr ll INF = 1e16;
constexpr ld EPS = 1e-10;
constexpr ld PI = 3.141592653589793;
const string endn = "\n";
const string abc = "abcdefghijklmnopqrstuvwxyz";
const string ABC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
template <class T1, class T2>
ostream &operator<<(ostream &out, const pair<T1, T2> &o) {
  out << "(" << o.first << ", " << o.second << ")";
  return out;
}
template <class T>
ostream &operator<<(ostream &out, const vector<T> &o) {
  for (auto itr = o.begin(); itr != o.end(); itr++)
    out << *itr << (itr + 1 != o.end() ? " " : "");
  return out;
}
template <class T>
ostream &operator<<(ostream &out, const deque<T> &o) {
  for (auto itr = o.begin(); itr != o.end(); itr++)
    out << *itr << (itr + 1 != o.end() ? " " : "");
  return out;
}
template <class T>
ostream &operator<<(ostream &out, const set<T> &o) {
  out << "{";
  for (auto itr = o.begin(); itr != o.end(); itr++)
    out << *itr << (next(itr, 1) != o.end() ? "," : "");
  out << "}";
  return out;
}
template <class T>
ostream &operator<<(ostream &out, const multiset<T> &o) {
  out << "{";
  for (auto itr = o.begin(); itr != o.end(); itr++)
    out << *itr << (next(itr, 1) != o.end() ? "," : "");
  out << "}";
  return out;
}
template <class T, class U>
ostream &operator<<(ostream &out, const map<T, U> &o) {
  out << "{";
  for (auto itr = o.begin(); itr != o.end(); itr++)
    out << *itr << (next(itr, 1) != o.end() ? " " : "");
  out << "}";
  return out;
}
template <class T, class U>
ostream &operator<<(ostream &out, const multimap<T, U> &o) {
  out << "{";
  for (auto itr = o.begin(); itr != o.end(); itr++)
    out << *itr << (next(itr, 1) != o.end() ? " " : "");
  out << "}";
  return out;
}
template <class T>
ostream &operator<<(ostream &out, queue<T> o) {
  while (!o.empty()) out << o.front() << (o.size() > 0 ? " " : ""), o.pop();
  return out;
}
template <class T, class U>
ostream &operator<<(ostream &out, priority_queue<T, vector<T>, U> o) {
  while (!o.empty()) out << o.top() << (o.size() > 0 ? " " : ""), o.pop();
  return out;
}
template <class T>
ostream &operator<<(ostream &out, stack<T> o) {
  while (!o.empty()) out << o.top() << (o.size() > 0 ? " " : ""), o.pop();
  return out;
}
template <class T>
inline bool chmin(T &a, T b) {
  if (a >= b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmax(T &a, T b) {
  if (a <= b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmin(T &a, initializer_list<T> b) {
  T c = min(b);
  if (a > c) {
    a = c;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmax(T &a, initializer_list<T> b) {
  T c = max(b);
  if (a < c) {
    a = c;
    return 1;
  }
  return 0;
}
inline ll mrep(ll &a, ll M = MOD) {
  a %= M;
  return a = (a < 0 ? a + M : a);
}
inline ll add(ll &a, ll b, ll M = MOD) {
  return a = (mrep(a, M) + mrep(b, M)) % M;
}
inline ll mul(ll &a, ll b, ll M = MOD) {
  return a = (mrep(a, M) * mrep(b, M)) % M;
}
inline ll add(ll &a, initializer_list<ll> b, ll M = MOD) {
  return a = (mrep(a, M) + accumulate(b.begin(), b.end(), (ll)0,
                                      [&M](ll acc, ll i) {
                                        return (acc + mrep(i, M)) % M;
                                      })) %
             M;
}
inline ll mul(ll &a, initializer_list<ll> b, ll M = MOD) {
  return a = (mrep(a, M) * accumulate(b.begin(), b.end(), (ll)1,
                                      [&M](ll acc, ll i) {
                                        return (acc * mrep(i, M)) % M;
                                      })) %
             M;
}
inline ll modpow(ll b, ll e, ll M = MOD) {
  ll ret = 1;
  while (e > 0) {
    if (e % 2) mul(ret, b, M);
    mul(b, b, M);
    e /= 2;
  };
  return ret;
}
inline ll modinv(ll a, ll M = MOD) {
  ll b = M, u = 1, v = 0;
  while (b) {
    ll t = a / b;
    a -= t * b;
    swap(a, b);
    u -= t * v;
    swap(u, v);
  }
  return mrep(u, M);
}
template <class T>
inline void print(T a) {
  cout << a << endl;
}
template <class T>
inline void print(vector<T> a, ll n) {
  chmin(n, ll(a.size()));
  for (ll i = 0; i < ll(n); i++) cout << a[i] << (i != n - 1 ? " " : "\n");
}
template <class T, size_t SIZE>
inline void print(T (&a)[SIZE], ll n = SIZE) {
  chmin(n, ll(SIZE));
  for (ll i = 0; i < ll(n); i++) cout << a[i] << (i != n - 1 ? " " : "\n");
}
inline string yesno(bool b) { return (b ? "Yes" : "No"); }
#pragma #endregion tmp
signed main() {
  ll h, w;
  cin >> h >> w;
  bool b = true;
  bool s[60][60];
  for (ll i = 0; i < ll(60); i++)
    for (ll j = 0; j < ll(60); j++) s[i][j] = false;
  for (ll i = 1; i < ll(h + 1); i++) {
    for (ll j = 1; j < ll(w + 1); j++) {
      char c;
      cin >> c;
      s[i][j] = (c == '#');
    }
  }
  for (ll i = 1; i < ll(h + 1); i++) {
    for (ll j = 1; j < ll(w + 1); j++) {
      b = (!s[i][j] || s[i - 1][j] || s[i + 1][j] || s[i][j - 1] ||
           s[i][j + 1]);
    }
  }
  cout << yesno(b) << endl;
}
