from collections import Counter
def solution(k, tangerine):
answer = 0
infos = Counter(tangerine)
infos = dict(sorted(infos.items(), key=lambda x:-x[1]))
for key, val in infos.items():
k -= val
answer += 1
if k <= 0:
break
return answer
출처: 프로그래머스 코딩 테스트 연습, https://school.programmers.co.kr/learn/challenges