##################################
#                                #
# Last modified 2020/11/16       # 
#                                #
# Georgi Marinov                 #
#                                # 
##################################

import sys
import string

def getReverseComplement(preliminarysequence):
    
    DNA = {'A':'T','T':'A','G':'C','C':'G','N':'N','a':'t','t':'a','g':'c','c':'g','n':'n'}
    sequence=''
    for j in range(len(preliminarysequence)):
        sequence=sequence+DNA[preliminarysequence[len(preliminarysequence)-j-1]]
    return sequence

def run():

    if len(sys.argv) < 2:
        print 'usage: python %s fasta outputfilename' % sys.argv[0]
        sys.exit(1)

    fasta = sys.argv[1]
    outfilename = sys.argv[2]

    GenomeDict={}
    sequence=''
    inputdatafile = open(fasta)
    for line in inputdatafile:
        if line[0]=='>':
            if sequence != '':
                GenomeDict[chr] = ''.join(sequence)
            chr = line.strip().split('>')[1]
            print chr
            sequence=[]
            continue
        else:
            sequence.append(line.strip())
    GenomeDict[chr] = ''.join(sequence)

    outfile = open(outfilename, 'w')

    chromosomes = GenomeDict.keys()
    chromosomes.sort()

    for chr in chromosomes:
        outline = '>' + chr
        sequence = GenomeDict[chr]
        outfile.write(outline + '\n')
        outfile.write(getReverseComplement(sequence) + '\n')

    outfile.close()
   
run()