Rpi Event From 4 input key

import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM)
GPIO.setup(17,GPIO.IN,pull_up_down=GPIO.PUD_UP)
GPIO.setup(18,GPIO.IN,pull_up_down=GPIO.PUD_UP)
GPIO.setup(6,GPIO.IN,pull_up_down=GPIO.PUD_UP)
GPIO.setup(23,GPIO.IN,pull_up_down=GPIO.PUD_UP)
GPIO.setup(5,GPIO.OUT)
def prints(CH) :
    print ('Button', CH, 'Pressed')
try :
    GPIO.add_event_detect(17,GPIO.RISING,callback=prints,bouncetime=300)
    GPIO.add_event_detect(18,GPIO.RISING,callback=prints,bouncetime=300)
    GPIO.add_event_detect(6,GPIO.RISING,callback=prints,bouncetime=300)
    GPIO.add_event_detect(23,GPIO.RISING,callback=prints,bouncetime=300)
    while True :
        GPIO.output(5,1)
        time.sleep(0.2)
        GPIO.output(5,0)
        time.sleep(0.2)
finally :
    GPIO.cleanup()