The four football teams of Dongshan, Xishan, Nanshan and Beishan held a friendly match. Each two teams played a match and played only one match. The final ranking according to the total number of goals: Dongshan> Xishan> Nanshan> Beishan. In each game, Dongshan team defeated Xishan team 4: 1, Beishan team defeated Nanshan team, and the other four games were tied. which is the least number of goals conceded by each team? ['Dongshan team.', 'West Hills.', 'Nanshan Team.', 'Beishan.']