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)

function Main(input) {
    var s = input;
    var k = input.length
    var oCount = 0;
    var xCount = 0;
    var res;
    for(var i = 0; i < k; i++){
        if(s[i] == "o"){
            oCount++
        }
        if(s[i] == "x"){
            xCount++
        }
    }
    if(oCount >= 8){
        res = "YES"
    }else{
        var a = 15 - k;
        if(8 < a + oCount){
            res = "YES"
        }else{
            res = "NO"
        }
    }
    console.log(res);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));