#include <bits/stdc++.h>
using namespace std;
template <class T>
T gcd(T a, T b) {
  return b ? gcd(b, a % b) : a;
}
template <class T>
void chmax(T& l, const T r) {
  l = max(l, r);
}
template <class T>
void chmin(T& l, const T r) {
  l = min(l, r);
}
void reader(int& x) {
  int k, m = 0;
  x = 0;
  for (;;) {
    (k) = getchar_unlocked();
    if (k == '-') {
      m = 1;
      break;
    }
    if ('0' <= k && k <= '9') {
      x = k - '0';
      break;
    }
  }
  for (;;) {
    (k) = getchar_unlocked();
    if (k < '0' || k > '9') break;
    x = x * 10 + k - '0';
  }
  if (m) x = -x;
}
void reader(long long& x) {
  int k, m = 0;
  x = 0;
  for (;;) {
    (k) = getchar_unlocked();
    if (k == '-') {
      m = 1;
      break;
    }
    if ('0' <= k && k <= '9') {
      x = k - '0';
      break;
    }
  }
  for (;;) {
    (k) = getchar_unlocked();
    if (k < '0' || k > '9') break;
    x = x * 10 + k - '0';
  }
  if (m) x = -x;
}
int reader(char c[]) {
  int i, s = 0;
  for (;;) {
    (i) = getchar_unlocked();
    if (i != ' ' && i != '\n' && i != '\r' && i != '\t' && i != EOF) break;
  }
  c[s++] = i;
  for (;;) {
    (i) = getchar_unlocked();
    if (i == ' ' || i == '\n' || i == '\r' || i == '\t' || i == EOF) break;
    c[s++] = i;
  }
  c[s] = '\0';
  return s;
}
template <class T, class S>
void reader(T& x, S& y) {
  reader(x);
  reader(y);
}
template <class T, class S, class U>
void reader(T& x, S& y, U& z) {
  reader(x);
  reader(y);
  reader(z);
}
template <class T, class S, class U, class V>
void reader(T& x, S& y, U& z, V& w) {
  reader(x);
  reader(y);
  reader(z);
  reader(w);
}
void writer(int x, char c) {
  int s = 0, m = 0;
  char f[10];
  if (x < 0) m = 1, x = -x;
  while (x) f[s++] = x % 10, x /= 10;
  if (!s) f[s++] = 0;
  if (m) putchar_unlocked('-');
  while (s--) putchar_unlocked(f[s] + '0');
  putchar_unlocked(c);
}
void writer(long long x, char c) {
  int s = 0, m = 0;
  char f[20];
  if (x < 0) m = 1, x = -x;
  while (x) f[s++] = x % 10, x /= 10;
  if (!s) f[s++] = 0;
  if (m) putchar_unlocked('-');
  while (s--) putchar_unlocked(f[s] + '0');
  putchar_unlocked(c);
}
void writer(const char c[]) {
  int i;
  for (i = 0; c[i] != '\0'; i++) putchar_unlocked(c[i]);
}
void writer(const char x[], char c) {
  int i;
  for (i = 0; x[i] != '\0'; i++) putchar_unlocked(x[i]);
  putchar_unlocked(c);
}
template <class T>
void writerLn(T x) {
  writer(x, '\n');
}
template <class T, class S>
void writerLn(T x, S y) {
  writer(x, ' ');
  writer(y, '\n');
}
template <class T, class S, class U>
void writerLn(T x, S y, U z) {
  writer(x, ' ');
  writer(y, ' ');
  writer(z, '\n');
}
template <class T>
void writerArr(T x[], int n) {
  if (!n) {
    putchar_unlocked('\n');
    return;
  }
  for (int i = 0; i < (n - 1); i++) writer(x[i], ' ');
  writer(x[n - 1], '\n');
}
int n, m;
char t[500][501];
bool used[500][501];
int r1, c1, r2, c2;
const int d[] = {1, 0, -1, 0, 1};
bool dfs(int r, int c) {
  if (r == r2 && c == c2) return true;
  used[r][c] = true;
  if ((r != r1 || c != c1) && t[r][c] == 'X') return false;
  for (int i = 0; i < (4); i++) {
    int nr = r + d[i], nc = c + d[i + 1];
    if (0 <= nr && nr < n && 0 <= nc && nc < m && !used[nr][nc]) {
      bool b = dfs(nr, nc);
      if (b) return b;
    }
  }
  return false;
}
int main() {
  cin >> n >> m;
  for (int i = 0; i < (n); i++) cin >> t[i];
  cin >> r1 >> c1 >> r2 >> c2;
  r1--;
  c1--;
  r2--;
  c2--;
  int ct = 0;
  for (int i = 0; i < (4); i++) {
    int nr = r2 + d[i], nc = c2 + d[i + 1];
    if (0 <= nr && nr < n && 0 <= nc && nc < m) {
      if (t[nr][nc] == '.') ct++;
    }
  }
  bool ok = dfs(r1, c1);
  if (t[r2][c2] != 'X') {
    if (abs(r1 - r2) + abs(c1 - c2) == 1) {
      if (ct <= 0) ok = false;
    } else {
      if (ct <= 1) ok = false;
    }
  }
  if (r1 == r2 && c1 == c2) {
    if (ct >= 1)
      ok = true;
    else
      ok = false;
  }
  puts(ok ? "YES" : "NO");
}
