Being the most handsome guy of Nirma, Hardik likes to write letters to the girls having SENDNODES written in it. Now he is out of the ink but he still wants to send the letters.
He has a paper having some string consists of all uppercase letter written on it. Now he can cut any character from this paper and try to form the message SENDNODES. After forming the message, he sticks all those characters to the paper and send it to a single girl. Now he wants to find out that to how many different girls he can send the letters.
Input Format:
First line contains N, Length of astring written on the paper.
Next line contains a string written on the paper.
Output Format:
A single Integer, Maximum number of letters Hardik can send to the girls.
Constraints:
1<=N<=10^6
For the string "OSENDESND".
He can cut "SEND" from it first. Remaining string: "OESND"
Now he can cut N from it and put it before "O" : "NOESD"
Now he can put D before E to form another word: "NODES".
At last he can put both strings together ("SEND", "NODES") to form "SENDNODES".
