! voter rule
PROGRAM ex6_9

  IMPLICIT NONE
  INTEGER :: voter(1:20), neighbors(1:20), i = 0

  PRINT *, 'Input initial bits for 20 members:'
  READ *, voter(1:20)
  PRINT '(I3, ":", 20I2)', i, voter(1:20)

  DO i = 1, 5
    neighbors = CSHIFT( voter, 1 ) + CSHIFT( voter, -1 )
    WHERE( neighbors /= 1 ) voter = neighbors / 2
    PRINT '(I3, ":", 20I2)', i, voter(1:20)
  END DO

END PROGRAM ex6_9