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: Accepted)

program siax
  implicit none
  integer :: N,l,i

  real(8) :: c,d,e
  character(len=15) :: S
  read(*,*) S
  l=0
  do i=1,len_trim(S)
     if(S(i:i).eq.'o') then
        l=l+1
     endif
  enddo
  if((15-len_trim(S)+l).lt.8) then
     write(*,'(a)') 'NO'
  else
     write(*,'(a)') 'YES'
  endif
!  write(*,'(i0)') l                                                                                                                                     
end program siax