// #pragma GCC target("avx2")
#pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#include<atcoder/maxflow>
using namespace std;

using P = pair<int, int>;

const int M = 998244353;
const long long LM = 1LL << 60;


int main() {
    cin.tie(0);
    ios::sync_with_stdio(0);
    int h, w;
    cin >> h >> w;
    vector<string> s(h);
    for (int i = 0; i < h; ++i) {
        cin >> s[i];
    }
    atcoder::mf_graph<int> mf(h * w + 2);
    int S = h * w, T = h * w + 1;
    for (int i = 0; i < h; ++i) {
        for (int j = 0; j < w; ++j) {
            if (s[i][j] == 'h') {
                for (int k = i + 1; k < h; ++k) {
                    if (s[k][j] == 'h') {
                        break;
                    }
                    if (s[k][j] == 'r') {
                        mf.add_edge(i * w + j, k * w + j, 1);
                    }
                }
                for (int k = i - 1; k >= 0; --k) {
                    if (s[k][j] == 'h') {
                        break;
                    }
                    if (s[k][j] == 'r') {
                        mf.add_edge(i * w + j, k * w + j, 1);
                    }
                }
                for (int k = j + 1; k < w; ++k) {
                    if (s[i][k] == 'h') {
                        break;
                    }
                    if (s[i][k] == 'r') {
                        mf.add_edge(i * w + j, i * w + k, 1);
                    }
                }
                for (int k = j - 1; k >= 0; --k) {
                    if (s[i][k] == 'h') {
                        break;
                    }
                    if (s[i][k] == 'r') {
                        mf.add_edge(i * w + j, i * w + k, 1);
                    }
                }
            }
        }
    }
    int c = 0;
    for (int i = 0; i < h; ++i) {
        for (int j = 0; j < w; ++j) {
            if (s[i][j] == 'h') {
                mf.add_edge(S, i * w + j, 1);
            }
            if (s[i][j] == 'r') {
                mf.add_edge(i * w + j, T, 1);
                ++c;
            }
        }
    }
    int cc = mf.flow(S, T);
    if (c == cc) {
        cout << "Yes\n";
    }
    else {
        cout << "No\n";
    }

    return 0;
}