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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include<bits/stdc++.h>
#include<iomanip>
#define mins(a,b) a=min(a,b)
#define maxs(a,b) a=max(a,b)
template < typename T > std::string to_string( const T& n )
  {
    std::ostringstream stm ;
    stm << n ;
    return stm.str() ;
  }
using namespace std;

const long long INF=9000000000000000;
int main(){
long long int n=0,m=0,k;
string s;
cin>>s;
n=s.size();
for(int i=0;i<n;i++){
  if(s[i]=='o')
  m++;
}
if((15-n)<(8-m))
cout<<"NO"<<endl;
else
cout<<"YES"<<endl;
}