from collections import Counter
def solution(a):
elements = Counter(a)
answer = -1
for k in elements.keys():
if elements[k] <= answer:
continue
common_cnt = 0
idx = 0
print(k, answer)
while idx < len(a)-1:
#현재 검사하고 하는 k가 둘다 없는 경우
#둘이 같은 경우
if (a[idx] != k and a[idx+1] != k) or (a[idx] == a[idx+1]):
idx+=1
continue
common_cnt += 1
idx += 2
answer = max(common_cnt, answer)
if answer == -1:
return 0
else:
return answer * 2
print(solution([5,2,3,3,5,3]))