#!/usr/bin/python
# renumber file and mark the chains
#

import os
import sys
import string

lines = sys.stdin.readlines()

chain = 'A'
lastnum = 0
for line in lines:
	if len(line)<4 or line[:4]<>"ATOM":
		continue
	thisnum = int(line[5:11])
	if thisnum<lastnum:
		lastnum += 1
		if thisnum==1:
			chain = chr(ord(chain)+1)
		line = line[:5]+("%-6i" % (lastnum))+line[:11]
	else:
		lastnum = thisnum
	line = line[1:20]+chain+line[21:]
	print line,