#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int, int>
#define all(x) (x).begin(),(n).end()
signed main(){
ios::sync_with_stdio(false);
cin.tie(NULL);
int n, m, k, l; cin >> n >> m >> k >> l;
vector<vector<char> > mat(n, vector<char>(m));
int x1, y1, x2, y2; cin >> x1 >> y1 >> x2 >> y2;
int qx=0, qy=0;
vector<vector<int> > num_ver, num_hor, pas_ver, pas_hor;
num_ver.resize(n, vector<int>(m));
num_hor.resize(n, vector<int>(m));
pas_ver.resize(n, vector<int>(m));
pas_hor.resize(n, vector<int>(m));
for(int i=0; i<n; i++){
for(int j=0; j<m; j++){
cin >> mat[i][j];
if(mat[i][j]=='X'){
num_ver[i][j]=0;
num_hor[i][j]=0;
}else if(mat[i][j]=='*'){
qx=i;
qy=j;
}
else{
if(i==0){
num_ver[i][j]=1;
}else{
num_ver[i][j]=num_ver[i-1][j]+1;
}
if(j==0){
num_hor[i][j]=1;
}else{
num_hor[i][j]=num_hor[i][j-1]+1;
}
}
}
}
for(int i=n-1; i>=0; i--){
for(int j=m-1; j>=0; j--){
if(mat[i][j]=='x'){
num_ver[i][j]=0;
num_hor[i][j]=0;
}else{
if(i!=n-1){
num_ver[i][j]=max(num_ver[i+1][j], num_ver[i][j]);
}
if(j!=m-1){
num_hor[i][j]=max(num_hor[i][j+1], num_hor[i][j]);
}
}
if(num_ver[i][j]>=l)pas_ver[i][j]=1;
if(num_hor[i][j]>=k)pas_hor[i][j]=1;
}
}
vector<vector<int> > marc(n, vector<int>(m));
queue<pii> pos;
vector<pii> viz = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};
pos.push({x1, y2});
marc[x1][y2]=1;
while(!pos.empty()){
int x=pos.front().first;
int y=pos.front().second;
pos.pop();
for(pii p:viz){
int ax=p.first;
int ay=p.second;
int nx=x+ax;
int ny=y+ay;
if(nx>=0&&ny>=0&&nx<n&&ny<m&&!marc[nx][ny]&&pas_ver[nx][ny]+pas_hor[nx][ny]==2){
pos.push({nx, ny});
marc[nx][ny]=1;
}
}
}
if(marc[qx][qy]){
cout << "YES"<<endl;
}else{
cout << "NO"<<endl;
}
}
