using System; using System.IO; using System.Linq; using System.Text; using System.Diagnostics; using System.Collections.Generic; using System.Text.RegularExpressions; using Enu = System.Linq.Enumerable; class Program { static readonly int[] DR = { 0, 0, -1, 1 }; static readonly int[] DC = { -1, 1, 0, 0 }; void Solve() { int N = reader.Int(), HP = reader.Int(); int OX = reader.Int() - 1, OY = reader.Int() - 1; var grid = reader.IntGrid(N); var dp = new int[N, N, 2]; // r, c, used dp[0, 0, 0] = HP; var que = new Queue(); que.Enqueue(0); que.Enqueue(0); que.Enqueue(0); Func IsInside = (r, c) => r >= 0 && r < N && c >= 0 && c < N; while (que.Count > 0) { int r = que.Dequeue(), c = que.Dequeue(), used = que.Dequeue(); int hp = dp[r, c, used]; if (used == 0 && r == OY && c == OX) { hp *= 2; used = 1; } for (int d = 0; d < DR.Length; d++) { int nr = r + DR[d], nc = c + DC[d]; if (!IsInside(nr, nc)) continue; int nextHp = hp - grid[nr][nc]; if (nextHp > dp[nr, nc, used]) { if (nr == N - 1 && nc == N - 1) { Console.WriteLine("YES"); return; } dp[nr, nc, used] = nextHp; que.Enqueue(nr); que.Enqueue(nc); que.Enqueue(used); } } } Console.WriteLine("NO"); } Reader reader = new Reader(Console.In); static void Main() { new Program().Solve(); } } class Reader { private readonly TextReader reader; private readonly char[] separator = { ' ' }; private readonly StringSplitOptions removeOp = StringSplitOptions.RemoveEmptyEntries; private string[] A = new string[0]; private int i; public Reader(TextReader r) { reader = r; } public bool HasNext() { return Enqueue(); } public string String() { return Dequeue(); } public int Int() { return int.Parse(Dequeue()); } public long Long() { return long.Parse(Dequeue()); } public double Double() { return double.Parse(Dequeue()); } public int[] IntLine() { var s = Line(); return s == "" ? new int[0] : Array.ConvertAll(Split(s), int.Parse); } public int[] IntArray(int N) { return Enu.Range(0, N).Select(i => Int()).ToArray(); } public int[][] IntGrid(int H) { return Enu.Range(0, H).Select(i => IntLine()).ToArray(); } public string[] StringArray(int N) { return Enu.Range(0, N).Select(i => Line()).ToArray(); } public string Line() { return reader.ReadLine().Trim(); } private string[] Split(string s) { return s.Split(separator, removeOp); } private bool Enqueue() { if (i < A.Length) return true; string line = reader.ReadLine(); if (line == null) return false; if (line == "") return Enqueue(); A = Split(line); i = 0; return true; } private string Dequeue() { Enqueue(); return A[i++]; } }