#include <iostream>
#include <bits/stdc++.h>

using namespace std;
bool checkBoundries(int r , int c , int x , int y);
void pathesOfWolf(vector< vector<char> > arr (rows , vector<char>(columns)));


int main()
{
    int rows , columns;
    cin >> rows >> columns;
    bool f = false;
    char c;
    vector< vector<char> > arr (rows , vector<char>(columns));
    vector < pair<int,int> >wolfs;
    vector < vector<bool> > visited(rows , vector<bool>(columns, false));
    for(int i = 0; i < rows; i++)
    {
        for (int j = 0; j < columns; j++)
        {
            cin >> c;
            if(c == 'W')
            {
                wolfs.push_back(make_pair(i,j));
            }
            arr[i][j] = c;
        }
    }
    for( int i = 0; i < wolfs.size(); i ++)
    {
        int x , y;
        x = wolfs.at(wolfs.size()-1).first;
        y = wolfs.at(wolfs.size()-1).second;
        if(checkBoundries(rows , columns ,x + 1 , y) && arr[x + 1][y] == 'S' )
        {
            f = true;
            break;
        }
        else if(checkBoundries(rows , columns ,x  , y + 1) && arr[x ][y +1] == 'S' )
        {
            f = true;
            break;
        }
        else if(checkBoundries(rows , columns ,x -1 , y ) && arr[x -1][y] == 'S' )
        {
            f = true;
            break;
        }
        else if(checkBoundries(rows , columns ,x  , y - 1) && arr[x][y - 1] == 'S' )
        {
            f = true;
            break;
        }
        wolfs.erase(wolfs.end() - 1);
    }
    if(f){
        cout << "No";
    }
    else{


    }



}
bool checkBoundries(int r , int c , int x , int y)
{
    if( x < 0 || x >= r || y < 0 || y >= c)
    {
        return false;
    }
    return true ;
}

void pathesOfWolf(vector< vector<char> > arr (rows , vector<char>(columns))){
}