When altos hornos zapla is the  home (1st leg) what is overall amount of 1st leg?
CREATE TABLE "losers_knockout" (
  "home_1st_leg" text,
  "home_2nd_leg" text,
  "1st_leg" text,
  "2nd_leg" text,
  "aggregate" text
);
SELECT COUNT("1st_leg") FROM "losers_knockout" WHERE "home_1st_leg"='Altos Hornos Zapla';