# -*- coding: utf-8 -*-


def main():
    s = input()
    t = 'oxx' * 4

    if s in t:
        print('Yes')
    else:
        print('No')


if __name__ == "__main__":
    main()

# -*- coding: utf-8 -*-


def main():
    s = input()
    t = 'oxx' * 4

    if s in t:
        print('Yes')
    else:
        print('No')


if __name__ == "__main__":
    main()

# -*- coding: utf-8 -*-