text: #!/usr/bin/env python3
  import rospy
  from std_msgs.msg import Int32
  
  rospy.init_node('fourth')
  pub = rospy.Publisher('fourth_up',Int32, queue_size=1)
  rate = rospy.Rate(20)
  n = 0
  def cb(message):
  	pub.publish(message.data*4)
  
  if __name__== '__main__':
  	rospy.init_node('fourth')
  	sub = rospy.Subscriber('third_up', Int32, cb)
  	rospy.spin()
  