SELECT COUNT(*) FROM table_204_664 WHERE "nationality" = 'russia'
what is the number of russian participants ?
CREATE TABLE table_204_664 (
    id number,
    "rank" number,
    "bib" number,
    "name" text,
    "nationality" text,
    "start" text,
    "penalties (p+p+s+s)" text,
    "time" text,
    "deficit" text
)