infile = open('apr2015','r')
outfile = open('outfile','w')
for line in infile:
    print line
    #outfile.write(line)
    outfile.write(line[0:3])
    outfile.write(line[3:])
    if line[0:3] == 'a21':
        outfile.write('a22'+line[3:])
        outfile.write('a23'+line[3:])
        outfile.write('a24'+line[3:])
infile.close()
outfile.close()