#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using namespace placeholders; using LL = long long; using ULL = unsigned long long; using VI = vector< int >; using VVI = vector< vector< int > >; using VS = vector< string >; using ISS = istringstream; using OSS = ostringstream; using PII = pair< int, int >; using VPII = vector< pair< int, int > >; template < typename T = int > using VT = vector< T >; template < typename T = int > using VVT = vector< vector< T > >; template < typename T = int > using LIM = numeric_limits< T >; template < typename T > inline istream& operator>>( istream &s, vector< T > &v ){ for ( T &t : v ) { s >> t; } return s; } template < typename T > inline ostream& operator<<( ostream &s, const vector< T > &v ){ for ( int i = 0; i < int( v.size() ); ++i ){ s << ( " " + !i ) << v[i]; } return s; } void in_impl(){}; template < typename T, typename... TS > void in_impl( T &head, TS &... tail ){ cin >> head; in_impl( tail ... ); } #define IN( T, ... ) T __VA_ARGS__; in_impl( __VA_ARGS__ ); template < typename T > struct getv_fmt; template <> struct getv_fmt< int >{ static constexpr const char *fmt = "%d"; }; template <> struct getv_fmt< long long >{ static constexpr const char *fmt = "%lld"; }; template < typename T > void getv( std::vector< T > &v ){ for_each( begin( v ), end( v ), []( T &a ){ scanf( getv_fmt< T >::fmt, &a ); } ); }; template < typename T > inline T fromString( const string &s ) { T res; istringstream iss( s ); iss >> res; return res; } template < typename T > inline string toString( const T &a ) { ostringstream oss; oss << a; return oss.str(); } #define NUMBERED( name, number ) NUMBERED2( name, number ) #define NUMBERED2( name, number ) name ## _ ## number #define REP1( n ) REP2( NUMBERED( REP_COUNTER, __LINE__ ), n ) #define REP2( i, n ) REP3( i, 0, n ) #define REP3( i, m, n ) for ( int i = ( int )( m ); i < ( int )( n ); ++i ) #define GET_REP( a, b, c, F, ... ) F #define REP( ... ) GET_REP( __VA_ARGS__, REP3, REP2, REP1 )( __VA_ARGS__ ) #define FOR( e, c ) for ( auto &&e : c ) #define ALL( c ) begin( c ), end( c ) #define AALL( a ) ( remove_all_extents< decltype( a ) >::type * )a, ( remove_all_extents< decltype( a ) >::type * )a + sizeof( a ) / sizeof( remove_all_extents< decltype( a ) >::type ) #define DRANGE( c, p ) begin( c ), begin( c ) + ( p ), end( c ) #define SZ( v ) ( (int)( v ).size() ) #define EXIST( c, e ) ( ( c ).find( e ) != ( c ).end() ) template < typename T > inline bool chmin( T &a, const T &b ){ if ( b < a ) { a = b; return true; } return false; } template < typename T > inline bool chmax( T &a, const T &b ){ if ( a < b ) { a = b; return true; } return false; } #define PB push_back #define EM emplace #define EB emplace_back #define BI back_inserter #define MP make_pair #define fst first #define snd second #define DUMP( x ) cerr << #x << " = " << ( x ) << endl constexpr int dy[] = { 0, 1, 0, -1 }; constexpr int dx[] = { 1, 0, -1, 0 }; int main() { cin.tie( 0 ); ios::sync_with_stdio( false ); cout << setprecision( 12 ) << fixed; IN( int, H, W ); IN( int, sy, sx, gy, gx ); --sy, --sx, --gy, --gx; VS board( H ); cin >> board; static int reachable[ 64 ][ 64 ]; reachable[ sy ][ sx ] = 1; queue< PII > que; que.EM( sy, sx ); const auto inside = [&]( const int y, const int x ) { return 0 <= y && y < H && 0 <= x && x < W; }; while ( !que.empty() ) { const int y = que.front().fst; const int x = que.front().snd; que.pop(); REP( d, 4 ) { const int ny = y + dy[d]; const int nx = x + dx[d]; if ( inside( ny, nx ) && !reachable[ ny ][ nx ] && abs( board[y][x] - board[ ny ][ nx ] ) <= 1 ) { reachable[ ny ][ nx ] = 1; que.EM( ny, nx ); } const int nny = ny + dy[d]; const int nnx = nx + dx[d]; if ( inside( nny, nnx ) && !reachable[ nny ][ nnx ] && board[y][x] == board[ nny ][ nnx ] && board[ ny ][ nx ] < board[y][x] ) { reachable[ nny ][ nnx ] = 1; que.EM( nny, nnx ); } } } cout << ( reachable[ gy ][ gx ] ? "YES" : "NO" ) << endl; return 0; }