#include <bits/stdc++.h>
using namespace std;
using ll = long long;

template<class T> istream& operator >> (istream& is, vector<T>& vec) {
    for(T& x : vec) is >> x;
    return is;
}

template<class T> ostream& operator << (ostream& os, const vector<T>& vec) {
    if(vec.empty()) return os;
    os << vec[0];
    for(auto it = vec.begin(); ++it != vec.end(); ) os << ' ' << *it;
    return os;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int h, w;
    cin >> h >> w;
    vector<string> A(h);
    cin >> A;
    vector dp(h, vector(w, vector<int>(4, -1)));
    vector dp2(h, vector<int>(w)), dp3(h, vector<int>(w));
    auto rec = [&](auto rec, int y, int x, int ds) -> int {
        if(y < 0 || x < 0 || y >= h || x >= w) return 0;
        if(dp[y][x][ds] != -1) return dp[y][x][ds];
        if(A[y][x] == '.') return dp[y][x][ds] = 0;
        return dp[y][x][ds] = 1 + rec(rec, y + (ds & 1 ? 1 : -1), x + (ds & 2 ? 1 : -1), ds);
    };
    for(int y = 0; y < h; y++){
        for(int x = 0; x < w; x++){
            if(A[y][x] == '.') continue;
            int ans = 1 << 30;
            for(int s = 0; s < 4; s++){
                ans = min(ans, rec(rec, y, x, s));
            }
            if(ans >= 2) dp2[y][x] = dp3[y][x] = ans;
        }
    }
    for(int y = 0; y + 1 < h; y++){
        for(int x = 0; x < w; x++){
            if(x + 1 < w) dp2[y + 1][x + 1] = max(dp2[y + 1][x + 1], dp2[y][x] - 1);
            if(x >= 1) dp2[y + 1][x - 1] = max(dp2[y + 1][x - 1], dp2[y][x] - 1);
        }
    }
    for(int y = h - 1; y >= 1; y--){
        for(int x = 0; x < w; x++){
            if(x + 1 < w) dp3[y - 1][x + 1] = max(dp3[y - 1][x + 1], dp3[y][x] - 1);
            if(x >= 1) dp3[y - 1][x - 1] = max(dp3[y - 1][x - 1], dp3[y][x] - 1);
        }
    }

    for(int y = 0; y < h; y++){
        for(int x = 0; x < w; x++){
            if(A[y][x] == '.') continue;
            if(dp2[y][x] + dp3[y][x] == 0){
                cout << "No\n";
                return 0;
            }
        }
    }
    cout << "Yes\n";
}