이상한 문자열 만들기

def solution(s):
    answer = ''
    cnt = 0
    for i, e in enumerate(s):
        if e.isalpha():
            if cnt % 2 == 0:
                answer += e.upper()
            else:
                answer += e.lower()
            cnt += 1
        else:
            answer += e
            cnt = 0
    return answer