package contest221007; import java.io.*; import java.util.ArrayDeque; import java.util.Arrays; import java.util.InputMismatchException; import java.util.Queue; import java.util.function.IntUnaryOperator; import java.util.function.LongUnaryOperator; public class E { InputStream is; FastWriter out; String INPUT = ""; public void solve() { // 1 stepずつ登ることによってしかエネルギーはたまらない // 7way連結成分上で保存則がある // 落ちる方には辺が引ける // 上がる方は、(上がる方の最大エネルギー-h)/2-1で移動できるなら辺が引ける // (上がる方の最大エネルギー-h)-1で移動できるところに辺を引いて、その辺をなるべく通らないように int H = ni(), W = ni(); int sr = ni()-1, sc = ni()-1; int gr = ni()-1, gc = ni()-1; char[][] map = nm(H, W); // cost*INF - (最大高度)? long U = 100000; long[] td = new long[(2*H)*W]; Arrays.fill(td, Long.MAX_VALUE / 2); MinHeapL q = new MinHeapL((2*H)*W); q.add(sr*W+sc, U*U); td[sr*W+sc] = U*U; while(q.size() > 0){ int cur = q.argmin(); long cost = q.min() % U; long maxh = U - q.min() /U; // tr(cur/W, cur%W, q.min(), maxh, cost); q.remove(cur); if(cur < H*W) { int r = cur / W, c = cur % W; { int P = Math.min(H-1, r + (int) maxh / 2 + 1); for (int i = c - 1; i <= c + 1; i += 2) { if (i >= 0 && i < W) { int nex = H * W + P * W + i; long nc = (U-maxh) * U + cost; if (td[nex] > nc) { td[nex] = nc; q.update(nex, td[nex]); } } } } { int P = Math.min(H-1, r + (int)maxh + 1); for (int i = c - 1; i <= c + 1; i += 2) { if (i >= 0 && i < W) { int nex = H * W + P * W + i; long nc = (U-maxh) * U + cost + 1; if (td[nex] > nc) { td[nex] = nc; q.update(nex, td[nex]); } } } } }else{ int r = cur / W - H, c = cur % W; if(map[r][c] == '.'){ int nex = r * W + c; long nc = (U-Math.max(maxh, r)) * U + cost; if (td[nex] > nc) { td[nex] = nc; q.update(nex, td[nex]); } } if(r > 0){ int nex = H*W + (r-1) * W + c; long nc = (U-maxh) * U + cost; if (td[nex] > nc) { td[nex] = nc; q.update(nex, td[nex]); } } } } long last = td[gr*W+gc]; if(last >= Long.MAX_VALUE / 3){ out.println(-1); return; } out.println(last % U); } public static class MinHeapL { public long[] a; public int[] map; public int[] imap; public int n; public int pos; public static long INF = Long.MAX_VALUE; public MinHeapL(int m) { n = Integer.highestOneBit((m+1)<<1); a = new long[n]; map = new int[n]; imap = new int[n]; Arrays.fill(a, INF); Arrays.fill(map, -1); Arrays.fill(imap, -1); pos = 1; } public long add(int ind, long x) { int ret = imap[ind]; if(imap[ind] < 0){ a[pos] = x; map[pos] = ind; imap[ind] = pos; pos++; up(pos-1); } return ret != -1 ? a[ret] : x; } public long update(int ind, long x) { int ret = imap[ind]; if(imap[ind] < 0){ a[pos] = x; map[pos] = ind; imap[ind] = pos; pos++; up(pos-1); }else{ a[ret] = x; up(ret); down(ret); } return x; } public long remove(int ind) { if(pos == 1)return INF; if(imap[ind] == -1)return INF; pos--; int rem = imap[ind]; long ret = a[rem]; map[rem] = map[pos]; imap[map[pos]] = rem; imap[ind] = -1; a[rem] = a[pos]; a[pos] = INF; map[pos] = -1; up(rem); down(rem); return ret; } public long min() { return a[1]; } public int argmin() { return map[1]; } public int size() { return pos-1; } public long get(int ind){ return a[imap[ind]]; } private void up(int cur) { // for(int c = cur, p = c>>>1;p >= 1 && (a[p] > a[c] || a[p] == a[c] && map[p] > map[c]);c>>>=1, p>>>=1){ for(int c = cur, p = c>>>1;p >= 1 && a[p] > a[c];c>>>=1, p>>>=1){ long d = a[p]; a[p] = a[c]; a[c] = d; int e = imap[map[p]]; imap[map[p]] = imap[map[c]]; imap[map[c]] = e; e = map[p]; map[p] = map[c]; map[c] = e; } } private void down(int cur) { for(int c = cur;2*c < pos;){ // int b = a[2*c] < a[2*c+1] || a[2*c] == a[2*c+1] && map[2*c] < map[2*c+1] ? 2*c : 2*c+1; // if(a[b] < a[c] || a[b] == a[c] && map[b] < map[c]){ int b = a[2*c] < a[2*c+1] ? 2*c : 2*c+1; if(a[b] < a[c]){ long d = a[c]; a[c] = a[b]; a[b] = d; int e = imap[map[c]]; imap[map[c]] = imap[map[b]]; imap[map[b]] = e; e = map[c]; map[c] = map[b]; map[b] = e; c = b; }else{ break; } } } } public static class DJSet { public int[] upper; public DJSet(int n) { upper = new int[n]; Arrays.fill(upper, -1); } public int root(int x) { return upper[x] < 0 ? x : (upper[x] = root(upper[x])); } public boolean equiv(int x, int y) { return root(x) == root(y); } public boolean unite(int x, int y) { x = root(x); y = root(y); if (x != y) { if (upper[y] < upper[x]) { int d = x; x = y; y = d; } upper[x] += upper[y]; upper[y] = x; } return x == y; } public int count() { int ct = 0; for (int u : upper) if (u < 0) ct++; return ct; } public int[][] toBucket() { int n = upper.length; int[][] ret = new int[n][]; int[] rp = new int[n]; for (int i = 0; i < n; i++) if (upper[i] < 0) ret[i] = new int[-upper[i]]; for (int i = 0; i < n; i++) { int r = root(i); ret[r][rp[r]++] = i; } return ret; } } public static void main(String[] args) { new E().run(); } public void run() { long S = System.currentTimeMillis(); is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes()); out = new FastWriter(System.out); solve(); out.flush(); long G = System.currentTimeMillis(); tr(G-S+"ms"); // Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){ // @Override // public void run() { // long s = System.currentTimeMillis(); // solve(); // out.flush(); // if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms"); // } // }; // t.start(); // t.join(); } private boolean eof() { if(lenbuf == -1)return true; int lptr = ptrbuf; while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false; try { is.mark(1000); while(true){ int b = is.read(); if(b == -1){ is.reset(); return true; }else if(!isSpaceChar(b)){ is.reset(); return false; } } } catch (IOException e) { return true; } } private final byte[] inbuf = new byte[1024]; public int lenbuf = 0, ptrbuf = 0; private int readByte() { if(lenbuf == -1)throw new InputMismatchException(); if(ptrbuf >= lenbuf){ ptrbuf = 0; try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); } if(lenbuf <= 0)return -1; } return inbuf[ptrbuf++]; } private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); } // private boolean isSpaceChar(int c) { return !(c >= 32 && c <= 126); } private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; } private double nd() { return Double.parseDouble(ns()); } private char nc() { return (char)skip(); } private String ns() { int b = skip(); StringBuilder sb = new StringBuilder(); while(!(isSpaceChar(b))){ sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } private char[] ns(int n) { char[] buf = new char[n]; int b = skip(), p = 0; while(p < n && !(isSpaceChar(b))){ buf[p++] = (char)b; b = readByte(); } return n == p ? buf : Arrays.copyOf(buf, p); } private char[][] nm(int n, int m) { char[][] map = new char[n][]; for(int i = 0;i < n;i++)map[i] = ns(m); return map; } private int[][] nmi(int n, int m) { int[][] map = new int[n][]; for(int i = 0;i < n;i++)map[i] = na(m); return map; } private int[] na(int n) { int[] a = new int[n]; for(int i = 0;i < n;i++)a[i] = ni(); return a; } private long[] nal(int n) { long[] a = new long[n]; for(int i = 0;i < n;i++)a[i] = nl(); return a; } private int ni() { int num = 0, b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } private long nl() { long num = 0; int b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } public static class FastWriter { private static final int BUF_SIZE = 1<<13; private final byte[] buf = new byte[BUF_SIZE]; private final OutputStream out; private int ptr = 0; private FastWriter(){out = null;} public FastWriter(OutputStream os) { this.out = os; } public FastWriter(String path) { try { this.out = new FileOutputStream(path); } catch (FileNotFoundException e) { throw new RuntimeException("FastWriter"); } } public FastWriter write(byte b) { buf[ptr++] = b; if(ptr == BUF_SIZE)innerflush(); return this; } public FastWriter write(char c) { return write((byte)c); } public FastWriter write(char[] s) { for(char c : s){ buf[ptr++] = (byte)c; if(ptr == BUF_SIZE)innerflush(); } return this; } public FastWriter write(String s) { s.chars().forEach(c -> { buf[ptr++] = (byte)c; if(ptr == BUF_SIZE)innerflush(); }); return this; } private static int countDigits(int l) { if (l >= 1000000000) return 10; if (l >= 100000000) return 9; if (l >= 10000000) return 8; if (l >= 1000000) return 7; if (l >= 100000) return 6; if (l >= 10000) return 5; if (l >= 1000) return 4; if (l >= 100) return 3; if (l >= 10) return 2; return 1; } public FastWriter write(int x) { if(x == Integer.MIN_VALUE){ return write((long)x); } if(ptr + 12 >= BUF_SIZE)innerflush(); if(x < 0){ write((byte)'-'); x = -x; } int d = countDigits(x); for(int i = ptr + d - 1;i >= ptr;i--){ buf[i] = (byte)('0'+x%10); x /= 10; } ptr += d; return this; } private static int countDigits(long l) { if (l >= 1000000000000000000L) return 19; if (l >= 100000000000000000L) return 18; if (l >= 10000000000000000L) return 17; if (l >= 1000000000000000L) return 16; if (l >= 100000000000000L) return 15; if (l >= 10000000000000L) return 14; if (l >= 1000000000000L) return 13; if (l >= 100000000000L) return 12; if (l >= 10000000000L) return 11; if (l >= 1000000000L) return 10; if (l >= 100000000L) return 9; if (l >= 10000000L) return 8; if (l >= 1000000L) return 7; if (l >= 100000L) return 6; if (l >= 10000L) return 5; if (l >= 1000L) return 4; if (l >= 100L) return 3; if (l >= 10L) return 2; return 1; } public FastWriter write(long x) { if(x == Long.MIN_VALUE){ return write("" + x); } if(ptr + 21 >= BUF_SIZE)innerflush(); if(x < 0){ write((byte)'-'); x = -x; } int d = countDigits(x); for(int i = ptr + d - 1;i >= ptr;i--){ buf[i] = (byte)('0'+x%10); x /= 10; } ptr += d; return this; } public FastWriter write(double x, int precision) { if(x < 0){ write('-'); x = -x; } x += Math.pow(10, -precision)/2; // if(x < 0){ x = 0; } write((long)x).write("."); x -= (long)x; for(int i = 0;i < precision;i++){ x *= 10; write((char)('0'+(int)x)); x -= (int)x; } return this; } public FastWriter writeln(char c){ return write(c).writeln(); } public FastWriter writeln(int x){ return write(x).writeln(); } public FastWriter writeln(long x){ return write(x).writeln(); } public FastWriter writeln(double x, int precision){ return write(x, precision).writeln(); } public FastWriter write(int... xs) { boolean first = true; for(int x : xs) { if (!first) write(' '); first = false; write(x); } return this; } public FastWriter write(long... xs) { boolean first = true; for(long x : xs) { if (!first) write(' '); first = false; write(x); } return this; } public FastWriter write(IntUnaryOperator f, int... xs) { boolean first = true; for(int x : xs) { if (!first) write(' '); first = false; write(f.applyAsInt(x)); } return this; } public FastWriter write(LongUnaryOperator f, long... xs) { boolean first = true; for(long x : xs) { if (!first) write(' '); first = false; write(f.applyAsLong(x)); } return this; } public FastWriter writeln() { return write((byte)'\n'); } public FastWriter writeln(int... xs) { return write(xs).writeln(); } public FastWriter writeln(long... xs) { return write(xs).writeln(); } public FastWriter writeln(IntUnaryOperator f, int... xs) { return write(f, xs).writeln(); } public FastWriter writeln(LongUnaryOperator f, long... xs) { return write(f, xs).writeln(); } public FastWriter writeln(char[] line) { return write(line).writeln(); } public FastWriter writeln(char[]... map) { for(char[] line : map)write(line).writeln();return this; } public FastWriter writeln(String s) { return write(s).writeln(); } private void innerflush() { try { out.write(buf, 0, ptr); ptr = 0; } catch (IOException e) { throw new RuntimeException("innerflush"); } } public void flush() { innerflush(); try { out.flush(); } catch (IOException e) { throw new RuntimeException("flush"); } } public FastWriter print(byte b) { return write(b); } public FastWriter print(char c) { return write(c); } public FastWriter print(char[] s) { return write(s); } public FastWriter print(String s) { return write(s); } public FastWriter print(int x) { return write(x); } public FastWriter print(long x) { return write(x); } public FastWriter print(double x, int precision) { return write(x, precision); } public FastWriter println(char c){ return writeln(c); } public FastWriter println(int x){ return writeln(x); } public FastWriter println(long x){ return writeln(x); } public FastWriter println(double x, int precision){ return writeln(x, precision); } public FastWriter print(int... xs) { return write(xs); } public FastWriter print(long... xs) { return write(xs); } public FastWriter print(IntUnaryOperator f, int... xs) { return write(f, xs); } public FastWriter print(LongUnaryOperator f, long... xs) { return write(f, xs); } public FastWriter println(int... xs) { return writeln(xs); } public FastWriter println(long... xs) { return writeln(xs); } public FastWriter println(IntUnaryOperator f, int... xs) { return writeln(f, xs); } public FastWriter println(LongUnaryOperator f, long... xs) { return writeln(f, xs); } public FastWriter println(char[] line) { return writeln(line); } public FastWriter println(char[]... map) { return writeln(map); } public FastWriter println(String s) { return writeln(s); } public FastWriter println() { return writeln(); } } public static void trnz(int... o) { for(int i = 0;i < o.length;i++)if(o[i] != 0)System.out.print(i+":"+o[i]+" "); System.out.println(); } // print ids which are 1 public static void trt(long... o) { Queue stands = new ArrayDeque<>(); for(int i = 0;i < o.length;i++){ for(long x = o[i];x != 0;x &= x-1)stands.add(i<<6|Long.numberOfTrailingZeros(x)); } System.out.println(stands); } public static void tf(boolean... r) { for(boolean x : r)System.out.print(x?'#':'.'); System.out.println(); } public static void tf(boolean[]... b) { for(boolean[] r : b) { for(boolean x : r)System.out.print(x?'#':'.'); System.out.println(); } System.out.println(); } public void tf(long[]... b) { if(INPUT.length() != 0) { for (long[] r : b) { for (long x : r) { for (int i = 0; i < 64; i++) { System.out.print(x << ~i < 0 ? '#' : '.'); } } System.out.println(); } System.out.println(); } } public void tf(long... b) { if(INPUT.length() != 0) { for (long x : b) { for (int i = 0; i < 64; i++) { System.out.print(x << ~i < 0 ? '#' : '.'); } } System.out.println(); } } private void tr(Object... o) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); } }