#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <algorithm>
#include <atcoder/all>
#include <bitset>
#include <cassert>
#include <cmath>
#include <ctime>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
using namespace atcoder;
typedef long long ll;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repr(i, n) for (int i = (int)(n)-1; i >= 0; i--)
#define repk(i, k, n) for (int i = k; i < (int)(n); i++)
#define all(v) v.begin(), v.end()
#define mod1 1000000007
#define mod2 998244353
#define mod3 100000007
#define vi vector<int>
#define vs vector<string>
#define vc vector<char>
#define vl vector<ll>
#define vb vector<bool>
#define vvi vector<vector<int>>
#define vvc vector<vector<char>>
#define vvl vector<vector<ll>>
#define vvb vector<vector<bool>>
#define vvvi vector<vector<vector<int>>>
#define vvvl vector<vector<vector<ll>>>
#define pii pair<int, int>
#define pil pair<int, ll>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define vpii vector<pair<int, int>>
#define vpll vector<pair<ll, ll>>
#define vvpii vector<vector<pair<int, int>>>
#define vvpll vector<vector<pair<ll, ll>>>

// using mint = modint998244353;

template <typename T>
void debug(T e) {
    cerr << e << endl;
}

template <typename T>
void debug(vector<T> &v) {
    rep(i, v.size()) { cerr << v[i] << " "; }
    cerr << endl;
}

template <typename T>
void debug(vector<vector<T>> &v) {
    rep(i, v.size()) {
        rep(j, v[i].size()) { cerr << v[i][j] << " "; }
        cerr << endl;
    }
}

template <typename T>
void debug(vector<pair<T, T>> &v) {
    rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; }
}

template <typename T>
void debug(set<T> &st) {
    for (auto itr = st.begin(); itr != st.end(); itr++) {
        cerr << *itr << " ";
    }
    cerr << endl;
}

template <typename T>
void debug(multiset<T> &ms) {
    for (auto itr = ms.begin(); itr != ms.end(); itr++) {
        cerr << *itr << " ";
    }
    cerr << endl;
}

template <typename T>
void debug(map<T, T> &mp) {
    for (auto itr = mp.begin(); itr != mp.end(); itr++) {
        cerr << itr->first << " " << itr->second << endl;
    }
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << H << " ";
    debug_out(T...);
}

int main() {
    ll H, W;
    cin >> H >> W;
    vector<string> S(H);
    for (ll i = 0; i < H; i++) {
        cin >> S[i];
    }
    vector<vector<ll>> sum1(H, vector<ll>(W, 0));
    vector<vector<ll>> sum2(H, vector<ll>(W, 0));
    vector<vector<ll>> sum3(H, vector<ll>(W, 0));
    vector<vector<ll>> sum4(H, vector<ll>(W, 0));
    for (ll i = 0; i < H; i++) {
        for (ll j = 0; j < W; j++) {
            if (S[i][j] == '#') {
                sum1[i][j] = 1;
                sum2[i][j] = 1;
                sum3[i][j] = 1;
                sum4[i][j] = 1;
            }
        }
    }
    for (ll i = 0; i < H; i++) {
        for (ll j = 0; j < W; j++) {
            if (S[i][j] == '.') {
                continue;
            }
            if (i > 0 && j > 0) {
                sum1[i][j] += sum1[i - 1][j - 1];
            }
        }
    }
    for (ll i = 0; i < H; i++) {
        for (ll j = W - 1; j >= 0; j--) {
            if (S[i][j] == '.') {
                continue;
            }
            if (i > 0 && j < W - 1) {
                sum2[i][j] += sum2[i - 1][j + 1];
            }
        }
    }
    for (ll i = H - 1; i >= 0; i--) {
        for (ll j = 0; j < W; j++) {
            if (S[i][j] == '.') {
                continue;
            }
            if (i < H - 1 && j > 0) {
                sum3[i][j] += sum3[i + 1][j - 1];
            }
        }
    }
    for (ll i = H - 1; i >= 0; i--) {
        for (ll j = W - 1; j >= 0; j--) {
            if (S[i][j] == '.') {
                continue;
            }
            if (i < H - 1 && j < W - 1) {
                sum4[i][j] += sum4[i + 1][j + 1];
            }
        }
    }
    // debug(sum1);
    // debug(sum2);
    // debug(sum3);
    // debug(sum4);
    vector<vector<ll>> radius(H, vector<ll>(W, 0));
    for (ll i = 0; i < H; i++) {
        for (ll j = 0; j < W; j++) {
            ll r = sum1[i][j];
            r = min(r, min(sum2[i][j], min(sum3[i][j], sum4[i][j])));
            radius[i][j] = r;
        }
    }
    // debug(radius);
    // あとは塗れるだけ実際に塗ってみて確かめよう
    vector<vector<ll>> imos1(H, vector<ll>(W, 0));
    vector<vector<ll>> imos2(H, vector<ll>(W, 0));
    vector<vector<ll>> imos3(H, vector<ll>(W, 0));
    vector<vector<ll>> imos4(H, vector<ll>(W, 0));
    for (ll i = 0; i < H; i++) {
        for (ll j = 0; j < W; j++) {
            if (radius[i][j] >= 2) {
                ll r = radius[i][j];
                imos1[i][j] += 1;
                if (i + r < H && j + r < W) {
                    imos1[i + r][j + r]--;
                }
                imos2[i][j] += 1;
                if (i + r < H && j - r >= 0) {
                    imos2[i + r][j - r]--;
                }
                imos3[i][j] += 1;
                if (i - r >= 0 && j + r < W) {
                    imos3[i - r][j + r]--;
                }
                imos4[i][j] += 1;
                if (i - r >= 0 && j - r >= 0) {
                    imos4[i - r][j - r]--;
                }
            }
        }
    }
    for (ll i = 0; i < H; i++) {
        for (ll j = 0; j < W; j++) {
            if (i > 0 && j > 0) {
                imos1[i][j] += imos1[i - 1][j - 1];
            }
        }
    }
    for (ll i = 0; i < H; i++) {
        for (ll j = W - 1; j >= 0; j--) {
            if (i > 0 && j < W - 1) {
                imos2[i][j] += imos2[i - 1][j + 1];
            }
        }
    }
    for (ll i = H - 1; i >= 0; i--) {
        for (ll j = 0; j < W; j++) {
            if (i < H - 1 && j > 0) {
                imos3[i][j] += imos3[i + 1][j - 1];
            }
        }
    }
    for (ll i = H - 1; i >= 0; i--) {
        for (ll j = W - 1; j >= 0; j--) {
            if (i < H - 1 && j < W - 1) {
                imos4[i][j] += imos4[i + 1][j + 1];
            }
        }
    }
    bool pos = true;
    for (ll i = 0; i < H; i++) {
        for (ll j = 0; j < W; j++) {
            if (S[i][j] == '#') {
                if (imos1[i][j] + imos2[i][j] + imos3[i][j] + imos4[i][j] ==
                    0) {
                    pos = false;
                }
            }
        }
    }
    if (pos) {
        cout << "Yes" << endl;
    } else {
        cout << "No" << endl;
    }
}