One day Alex was creating a contest about his friends, but accidentally deleted it. Fortunately, all the problems were saved, but now he needs to find them among other problems.

But there are too many problems, to do it manually. Alex asks you to write a program, which will determine if a problem is from this contest by its name.

It is known, that problem is from this contest if and only if its name contains one of Alex's friends' name exactly once. His friends' names are "Danil", "Olya", "Slava", "Ann" and "Nikita".

Names are case sensitive.

Input

The only line contains string from lowercase and uppercase letters and "_" symbols of length, not more than 100 — the name of the problem.

Output

Print "YES", if problem is from this contest, and "NO" otherwise.

Examples

Input

Alex_and_broken_contest


Output

NO

Input

NikitaAndString


Output

YES

Input

Danil_and_Olya


Output

NO
###################
# 27th August 2019.
###################

######################################################################
# Defining Class for Problem Solution.
class Solution:
    # Method to determine if there is a problem in the title.
    def isThereProblemInTitle(self):
        patterns = ['10000','01000','00100','00010','00001']
        return not self.countFriendNames() in patterns
    # Method to count occurences of Each Friend.
    def countFriendNames(self):
        counts = []
        for name in Solution.friends:
            counts.append(self.contestTitle.count(name))
        return "".join(map(str,counts))
    # Constructor.
    def __init__(self,contestTitle):
        self.contestTitle = contestTitle
    # Defining Friend Names.
    friends = ['Danil','Olya','Slava','Ann','Nikita']
# Making Solution Object.
solution = Solution(input())
# Verdict.
print('NO') if solution.isThereProblemInTitle() else print('YES')
######################################################################

                              ########################################
                              # Programming-Credits atifcppprogrammer.
                              ########################################
