#include <bits/stdc++.h>
using namespace std;
struct State {
int xh, yh, xv, yv;
};
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int W, H, K, L;
cin >> W >> H >> K >> L;
int xh0, yh0, xv0, yv0;
cin >> xh0 >> yh0 >> xv0 >> yv0;
vector<string> g(H);
for (int i = 0; i < H; i++) cin >> g[i];
int tx = -1, ty = -1;
for (int y = 0; y < H; y++) {
for (int x = 0; x < W; x++) {
if (g[y][x] == '*') {
tx = x;
ty = y;
}
}
}
// Row prefix sums for obstacles
vector<vector<int>> rowPref(H, vector<int>(W + 1, 0));
for (int y = 0; y < H; y++) {
for (int x = 0; x < W; x++) {
rowPref[y][x + 1] = rowPref[y][x] + (g[y][x] == 'X');
}
}
// Column prefix sums for obstacles
vector<vector<int>> colPref(W, vector<int>(H + 1, 0));
for (int x = 0; x < W; x++) {
for (int y = 0; y < H; y++) {
colPref[x][y + 1] = colPref[x][y] + (g[y][x] == 'X');
}
}
auto horiz_ok = [&](int xh, int yh) -> bool {
if (yh < 0 || yh >= H) return false;
if (xh < 0 || xh + K > W) return false;
return (rowPref[yh][xh + K] - rowPref[yh][xh] == 0);
};
auto vert_ok = [&](int xv, int yv) -> bool {
if (xv < 0 || xv >= W) return false;
if (yv < 0 || yv + L > H) return false;
return (colPref[xv][yv + L] - colPref[xv][yv] == 0);
};
auto valid = [&](int xh, int yh, int xv, int yv) -> bool {
if (!horiz_ok(xh, yh)) return false;
if (!vert_ok(xv, yv)) return false;
// Must overlap in exactly one cell
if (!(xh <= xv && xv < xh + K)) return false;
if (!(yv <= yh && yh < yv + L)) return false;
return true;
};
if (!valid(xh0, yh0, xv0, yv0)) {
cout << "NO\n";
return 0;
}
// Since constraints are not shown in the screenshot,
// we use hash-based visited for the state space.
auto encode = [&](int xh, int yh, int xv, int yv) -> unsigned long long {
unsigned long long a = (unsigned long long)xh;
unsigned long long b = (unsigned long long)yh;
unsigned long long c = (unsigned long long)xv;
unsigned long long d = (unsigned long long)yv;
return (((a * 3001ULL + b) * 3001ULL + c) * 3001ULL + d);
};
queue<State> q;
unordered_set<unsigned long long> vis;
vis.reserve(1 << 20);
q.push({xh0, yh0, xv0, yv0});
vis.insert(encode(xh0, yh0, xv0, yv0));
int dxh[8] = {-1, 1, 0, 0, 0, 0, 0, 0};
int dyh[8] = {0, 0, -1, 1, 0, 0, 0, 0};
int dxv[8] = {0, 0, 0, 0, -1, 1, 0, 0};
int dyv[8] = {0, 0, 0, 0, 0, 0, -1, 1};
while (!q.empty()) {
State cur = q.front();
q.pop();
int overlapX = cur.xv;
int overlapY = cur.yh;
if (overlapX == tx && overlapY == ty) {
cout << "YES\n";
return 0;
}
for (int dir = 0; dir < 8; dir++) {
int nxh = cur.xh + dxh[dir];
int nyh = cur.yh + dyh[dir];
int nxv = cur.xv + dxv[dir];
int nyv = cur.yv + dyv[dir];
if (!valid(nxh, nyh, nxv, nyv)) continue;
auto code = encode(nxh, nyh, nxv, nyv);
if (vis.insert(code).second) {
q.push({nxh, nyh, nxv, nyv});
}
}
}
cout << "NO\n";
return 0;
}
