What is the country with a course of merion golf club, and a to par [1] of e?
CREATE TABLE "u_s_open_champions" (
  "year" real,
  "country" text,
  "course" text,
  "location" text,
  "total_score" text,
  "to_par_a" text
);
SELECT "country" FROM "u_s_open_champions" WHERE "course"='merion golf club' AND "to_par_a"='e';