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.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Main {

	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		Task solver = new Task();
		solver.solve(1, in, out);
		out.close();

	}
	static class Task{
		public void solve(int testNumber, InputReader in, PrintWriter out) {
			char[] sc = in.next().toCharArray();
			int count_x = 0;
			for(char c: sc) if (c == 'x') count_x++;
			out.print(count_x<=7?"YES":"NO");
			
		}//Solve
	}//task
	
	
	static class InputReader{
		public BufferedReader reader;
		public StringTokenizer tokenizer;
		public InputReader(InputStream stream) {
			reader = new BufferedReader(new InputStreamReader(stream), 32768);
			tokenizer = null;
		}
		public String next() {
			while(tokenizer == null || ! tokenizer.hasMoreTokens()) {
				try {
					tokenizer = new StringTokenizer(reader.readLine());
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}
			return tokenizer.nextToken();
		}
		public int nextInt() {
			return Integer.parseInt(next());
		}
		public int[] nextIntArray(int n) {
			int[] a = new int[n];
			for(int i = -1; ++i < n;) a[i] = nextInt();
			return a;
		}
		public long nextLong() {
			return Long.parseLong(next());
		}
		public long[] nextLongArray(int n) {
			long[] a = new long[n];
			for(int i = -1; ++i < n;) a[i] = nextLong();
			return a;
		}
		public float nextFloat() {
			return Float.parseFloat(next());
		}
	}
}