# 1
# https://atcoder.jp/contests/diverta2019/tasks/diverta2019_a
if False:
    N,K=map(int,input().split())
    print(N-K+1)

# 2
# https://atcoder.jp/contests/m-solutions2019/tasks/m_solutions2019_b
if True:
    print('NO' if input().count('x')>7 else 'YES')


# 3
# https://atcoder.jp/contests/m-solutions2019/tasks/m_solutions2019_a

# 4
# https://atcoder.jp/contests/agc037/tasks/agc037_a


# 5
# https://atcoder.jp/contests/agc041/tasks/agc041_a if False:
    N,K=map(int,input().split())
    print(N-K+1)

# 2
# https://atcoder.jp/contests/m-solutions2019/tasks/m_solutions2019_b False N,K=map(int,input().split()) N map(int,input().split()) map int input().split() ().split () input split K print(N-K+1) print N-K+1 N-K N K 1 if True:
    print('NO' if input().count('x')>7 else 'YES')


# 3
# https://atcoder.jp/contests/m-solutions2019/tasks/m_solutions2019_a

# 4
# https://atcoder.jp/contests/agc037/tasks/agc037_a


# 5
# https://atcoder.jp/contests/agc041/tasks/agc041_a True print('NO' if input().count('x')>7 else 'YES') print 'NO' if input().count('x')>7 else 'YES' input().count('x')>7 input().count('x') ().count () input count 'x' 7 'NO' 'YES' K=map(int,input().split()) map(int,input().split()) K N,K=map(int,input().split()) map(int,input().split()) N
# 1
# https://atcoder.jp/contests/diverta2019/tasks/diverta2019_a
if False:
    N,K=map(int,input().split())
    print(N-K+1)

# 2
# https://atcoder.jp/contests/m-solutions2019/tasks/m_solutions2019_b
if True:
    print('NO' if input().count('x')>7 else 'YES')


# 3
# https://atcoder.jp/contests/m-solutions2019/tasks/m_solutions2019_a

# 4
# https://atcoder.jp/contests/agc037/tasks/agc037_a


# 5
# https://atcoder.jp/contests/agc041/tasks/agc041_a