W, H = gets.split.map{|i| i.to_i - 1} Sx, Sy, Gx, Gy = gets.split.map{|i| i.to_i - 1} Height = $<.read.split.map{|i| i.split('').map &:to_i} $able_to_go = [[Sx, Sy]] def candidate(ind) ary = [] h = Height[ind[0]][ind[1]] ary << [ind[0] - 1, ind[1]] if ind[0] > 0 && (Height[ind[0] - 1][ind[1]] - h).abs < 2 ary << [ind[0] + 1, ind[1]] if ind[0] < W && (Height[ind[0] + 1][ind[1]] - h).abs < 2 ary << [ind[0], ind[1] - 1] if ind[1] > 0 && (Height[ind[0]][ind[1] - 1] - h).abs < 2 ary << [ind[0], ind[1] + 1] if ind[1] < H && (Height[ind[0]][ind[0] + 1] - h).abs < 2 ary << [ind[0] - 2, ind[1]] if ind[0] > 1 && Height[ind[0] - 2][ind[1]] == h && Height[ind[0] - 1][ind[1]] < h ary << [ind[0] + 2, ind[1]] if ind[0] < W - 1 && Height[ind[0] + 2][ind[1]] == h && Height[ind[0] + 1][ind[1]] < h ary << [ind[0], ind[1] - 2] if ind[1] > 1 && Height[ind[0]][ind[1] - 2] == h && Height[ind[0]][ind[1] - 1] < h ary << [ind[0], ind[1] + 2] if ind[1] < H - 1 && Height[ind[0]][ind[1] + 2] == h && Height[ind[0]][ind[1] + 1] < h ary end def solve ((H + 1)*(W + 1)).times{|i| return :YES if $able_to_go.include?([Gx, Gy]) return :NO unless (_ = $able_to_go[i]) $able_to_go |= candidate(_) } end puts solve