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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

'use strict';

function main(stdin) {
  const input = stdin.split('').map(s => s === 'o' ? 1 : 0);
  const wins = new Array(15).fill(1);

  input.forEach((s, i) => {
    wins[i] = s;
  });

  if (wins.filter(s => s).length < 8) {
    console.log('NO');
  } else {
    console.log('YES');
  }
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));