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 Fortran (gfortran v4.8.4) (judge verdict: Wrong Answer)

program example
	implicit none

	character(15) S
    integer :: i=1,j,wa=0,k
    
    read(*,*) S
    
    k=len_trim(adjustl(S))
    
    do
    	if (i>k) then
        	exit
        end if
        
    	j=index(S(i:),"o")
        
    	if(j/=0) then
        	wa=wa+1
            i=i+j
        else
        	i=i+1
        end if
    end do
    
    if(wa>=8) then
    	write(*,*) "Yes"

	else
    	if((15-k)+wa>=8) then
        	write(*,*) "Yes"
    	else
        	write(*,*) "No"
        end if
    end if
end program example