Artur_2

input()
word = input().replace('?', '#').replace('*', '#')
i = word.index('X')

if word[-1] == '.':
    if set(word[i + 1:]) == {'.'}:
        if word[:i].find('.') < word[:i].rfind('#'):
            print('YES')
        else:
            print('NO')
    else:
        if '#' in word[i + 1:]:
            print('YES')
        else:
            print('NO')
else:
    print('NO')