#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A& a, const B& b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A& a, const B& b) { if (a > b) { a = b; return true; } return false; }

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int h, w; cin >> h >> w;
	vector<string>s(h);
	rep(i, h)cin >> s[i];
	vector<vector<int>>vh(h), vw(w);
	rep(i, h)rep(j, w) {
		if ('h' == s[i][j]) {
			vh[i].push_back(j);
			vw[j].push_back(i);
		}
	}
	int st = h * w;
	int ed = st + 1;
	mf_graph<int> g(ed + 1);
	auto trans = [&](int x, int y) {return x * w + y; };
	int cnt = 0;
	rep(i, h)rep(j, w) {
		if ('h' == s[i][j])g.add_edge(trans(i, j), ed, 1);
		if ('r' != s[i][j])continue;
		g.add_edge(st, trans(i, j), 1);
		cnt++;
		{
			int cnth = upper_bound(all(vh[i]), j) - vh[i].begin();
			if (0 != cnth) {
				int x = vh[i][cnth - 1];
				g.add_edge(trans(i, j), trans(i, x), 1);
			}
			if (vh[i].size() != cnth) {
				int x = vh[i][cnth];
				g.add_edge(trans(i, j), trans(i, x), 1);
			}
		}
		{
			int cntw = upper_bound(all(vw[j]), i) - vw[j].begin();
			if (0 != cntw) {
				int x = vw[j][cntw - 1];
				g.add_edge(trans(i, j), trans(x, j), 1);
			}
			if (vw[j].size() != cntw) {
				int x = vw[j][cntw];
				g.add_edge(trans(i, j), trans(x, j), 1);
			}
		}
	}
	int get = g.flow(st, ed);
	if (cnt == get)cout << "Yes" << endl;
	else cout << "No" << endl;
	return 0;
}