Problem:
Score : 200 points

Problem Statement

Takahashi is competing in a sumo tournament.
The tournament lasts for 15 days, during which he performs in one match per day.
If he wins 8 or more matches, he can also participate in the next tournament.

The matches for the first k days have finished.
You are given the results of Takahashi's matches as a string S consisting of o and x.
If the i-th character in S is o, it means that Takahashi won the match on the i-th day; if that character is x, it means that Takahashi lost the match on the i-th day.

Print YES if there is a possibility that Takahashi can participate in the next tournament, and print NO if there is no such possibility.

Constraints

1 \leq k \leq 15

S is a string of length k consisting of o and x.

Input

Input is given from Standard Input in the following format:

S

Output

Print YES if there is a possibility that Takahashi can participate in the next tournament, and print NO otherwise.

Sample Input 1

oxoxoxoxoxoxox

Sample Output 1

YES

Takahashi has 7 wins and 7 losses before the last match. If he wins that match, he will have 8 wins.

Sample Input 2

xxxxxxxx

Sample Output 2

NO

Solution in Java7 (OpenJDK 1.7.0) (judge verdict: Accepted)

import java.util.Scanner;
import java.util.InputMismatchException;

public class Main{
	public static void main(String[] args){
		try{
			Scanner scanner = new Scanner(System.in);
			String input = scanner.nextLine();
			
			String deleteMaru = input.replace("o", "");
			int maruNum = input.length() - deleteMaru.length();
			int finishedGames = input.length();
			
			if(15 - finishedGames + maruNum >= 8){
				System.out.println("YES");
			} else {
				System.out.println("NO");
			}
			
		} catch(IndexOutOfBoundsException e){
			e.printStackTrace();
		} catch(NumberFormatException e){
			e.printStackTrace();
		}
	}
}