WORD - WORD has a new addiction. Hunched over newspapers on WORD subway trains, sneaking secret peeks in the office, a puzzle-crazy nation is trying to slot WORD into small checkerboard grids. It`s Sudoku - a sort of crossword without words that has WORD the country. "There`s something about that grid with its empty squares - it`s just WORD out to be filled in," said Wayne Gould, a retired WORD and puzzle aficionado who helped spark WORD`s love affair with the WORD. A Japanese WORD that has quietly appeared in puzzle magazines in Asia and North America for years, Sudoku hit WORD in the pages of The Times newspaper in WORD. It now has thousands of avid followers, a host of Web sites and books, and runs daily in WORD national newspapers, which compete WORD to offer their readers the best puzzle. The Times is offering a version for WORD. The Daily Telegraph promises a 3-D "ultimate Sudoku" version. The name, which translates roughly as "the number that is alone," has become a handy catch-phrase. Sudoku consists of a grid of WORD rows of WORD boxes, which must be filled in so the numbers one through nine appear just once in each column, row and WORD-by-WORDWORD. It looks like WORD, but requires the application of WORD. It can be fairly straightforward or fiendishly difficult.