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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.PrintWriter;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        try (InputReader in = new InputReader(); PrintWriter out = new PrintWriter(System.out)) {
            new Main().solve(in, out);
            out.flush();
        }
    }

    void solve(InputReader in, PrintWriter out) {
        String s = in.next();

        int count = 0;
        for (char c : s.toCharArray()) {
            if (c == 'o') {
                count++;
            }
        }

        if (count + (15 - s.length()) >= 8) {
            out.println("YES");
        } else {
            out.println("NO");
        }
    }
}

class InputReader implements AutoCloseable {
    private final Scanner sc = new Scanner(System.in);

    String next() {
        return this.sc.next();
    }

    int nextInt() {
        return Integer.parseInt(this.sc.next());
    }

    long nextLong() {
        return Long.parseLong(this.sc.next());
    }

    double nextDouble() {
        return Double.parseDouble(this.sc.next());
    }

    @Override
    public void close() {
        this.sc.close();
    }
}