def solve(s):
    return "YES" if 7 >= s.count("x") else "NO"

s = input()
print(solve(s)) def solve(s):
    return "YES" if 7 >= s.count("x") else "NO" solve return "YES" if 7 >= s.count("x") else "NO" "YES" if 7 >= s.count("x") else "NO" 7 >= s.count("x") 7 s.count("x") s.count s count "x" "YES" "NO" s s s = input() s input() input print(solve(s)) print solve(s) solve s def solve(s):
    return "YES" if 7 >= s.count("x") else "NO" def solve(s):
    return "YES" if 7 >= s.count("x") else "NO" solve s = input() input() s
def solve(s):
    return "YES" if 7 >= s.count("x") else "NO"

s = input()
print(solve(s))