D

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

#define ll     long long
#define _test   int _TEST; cin>>_TEST; while(_TEST--)
#define ff     first
#define ss     second
#define pb     push_back

int main()
{
    int n, m;
    cin>>n>>m;

    vector<string> s(n);
    for(auto &e: s)     cin>>e;

    vector<vector<int>> vis(n, vector<int> (m, 0));

    string x = "snuke";

    int dx[4] = {1, 0, -1, 0};
    int dy[4] = {0, 1, 0, -1};

    function<void(int, int, int)> DFS = [&](int i, int j, int ind)
    {
        if(s[i][j] != x[ind])
            return;

        vis[i][j] = 1;

        for(int d=0; d<4; d++)
        {
            if(i+dx[d]>=0 && i+dx[d]<n && j+dy[d]>=0 && j+dy[d]<m)
            {
                if(!vis[i+dx[d]][j+dy[d]])
                    DFS(i+dx[d], j+dy[d], (ind+1)%5);
            }
        }
    };

    DFS(0, 0, 0);

    if(vis[n-1][m-1])       cout<<"Yes\n";
    else                    cout<<"No\n";
}