Who won men's singles when petya nedelcheva won women's singles, petya nedelcheva diana dimova won women's doubles, stilian makarski diana dimova won mixed doubles, and stilian makarski peyo boichinov won men's doubles?
CREATE TABLE "past_winners" (
  "year" real,
  "men_s_singles" text,
  "women_s_singles" text,
  "men_s_doubles" text,
  "women_s_doubles" text,
  "mixed_doubles" text
);
SELECT "men_s_singles" FROM "past_winners" WHERE "women_s_singles"='petya nedelcheva' AND "women_s_doubles"='petya nedelcheva diana dimova' AND "mixed_doubles"='stilian makarski diana dimova' AND "men_s_doubles"='stilian makarski peyo boichinov';