# Here your code ! def ser(x,y,d) return if(d==4) if(x == @x and y == @y) puts "YES" exit end ser(x-2,y-1,d+1) ser(x-2,y+1,d+1) ser(x-1,y-2,d+1) ser(x-1,y+2,d+1) ser(x+1,y-2,d+1) ser(x+1,y+2,d+1) ser(x+2,y-1,d+1) ser(x+2,y+1,d+1) end @x,@y=gets.chomp.split.map &:to_i ser(0,0,0) puts "NO"