"""
출처:프로그래머스,
https://school.programmers.co.kr/learn/courses/30/lessons/17680
"""
# 풀이 과정
def solution(cacheSize, cities):
    from collections import deque

    result = 0
    check = deque([])  # cache_list

    if cacheSize == 0:
        return len(cities) * 5

    for a in cities:
        a = a.upper()
        if len(check) < cacheSize:
            if a in check:
                i = check.index(a)
                del check[i]
                check.append(a)
                result += 1

            else:
                check.append(a)
                result += 5

        else:
            if a in check:
                i = check.index(a)
                del check[i]
                check.append(a)
                result += 1

            else:
                check.popleft()
                check.append(a)
                result += 5

    return result