Example
$ gunzip -c input.fastq.gz | paste - - - - | head
@IL31_4368:1:1:996:8507/2 TCCCTTACCCCCAAGCTCCATACCCTCCTAATGCCCACACCTCTTACCTTAGGA + FFCEFFFEEFFFFFFFEFFEFFFEFCFC<EEFEFFFCEFF<;EEFF=FEE?FCE
@IL31_4368:1:1:996:21421/2 CAAAAACTTTCACTTTACCTGCCGGGTTTCCCAGTTTACATTCCACTGTTTGAC + >DBDDB,B9BAA4AAB7BB?7BBB=91;+*@;5<87+*=/*@@?9=73=.7)7*
@IL31_4368:1:1:997:10572/2 GATCTTCTGTGACTGGAAGAAAATGTGTTACATATTACATTTCTGTCCCCATTG + E?=EECE<EEEE98EEEEAEEBD??BE@AEAB><EEABCEEDEC<<EBDA=DEE
@IL31_4368:1:1:997:15684/2 CAGCCTCAGATTCAGCATTCTCAAATTCAGCTGCGGCTGAAACAGCAGCAGGAC + EEEEDEEE9EAEEDEEEEEEEEEECEEAAEEDEE<CD=D=*BCAC?;CB,<D@,
@IL31_4368:1:1:997:15249/2 AATGTTCTGAAACCTCTGAGAAAGCAAATATTTATTTTAATGAAAAATCCTTAT + EDEEC;EEE;EEE?EECE;7AEEEEEE07EECEA;D6D>+EE4E7EEE4;E=EA
@IL31_4368:1:1:997:6273/2 ACATTTACCAAGACCAAAGGAAACTTACCTTGCAAGAATTAGACAGTTCATTTG + EEAAFFFEEFEFCFAFFAFCCFFEFEF>EFFFFB?ABA@ECEE=<F@DE@DDF;
@IL31_4368:1:1:997:1657/2 CCCACCTCTCTCAATGTTTTCCATATGGCAGGGACTCAGCACAGGTGGATTAAT + A;0A?AA+@A<7A7019/<65,3A;'''07<A=<=>?7=?6&)'9('*%,>/(<
@IL31_4368:1:1:997:5609/2 TCACTATCAGAAACAGAATGTATAACTTCCAAATCAGTAGGAAACACAAGGAAA + AEECECBEC@A;AC=<AEEEEAEEEE>AC,CE?ECCE9EAEC4E:<C>AC@EE)
@IL31_4368:1:1:997:14262/2 TGTTTTTTCTTTTTCTTTTTTTTTTGACAGTGCAGAGATTTTTTATCTTTTTAA + 97'<2<.64.?7/3(891?=(6??6+<6<++/*..3(:'/'9::''&(1<>.(,
@IL31_4368:1:1:998:19914/2 GAATGAAAGCAGAGACCCTGATCGAGCCCCAGAAAGATACACCTCCAGATTTTA + C?=CECE4CD<?8@==;EBE<=0@:@@92@???6<991>.<?A=@5?@99;971