我有这样的文件：
pw1jc5ssyt6hx618,254343
ysezaratlycpuggl,254333
pht92h4adr3mrbz3,254343
hguvgstqxu3gowfg,254344
gqjp2rsjmk1a2v9c,254333
twdzyi2ddbnrfknd,254333
gcmj7krrx5x6nf8r,254341
tpqorqbyrg1nmm7s,254333
alnac47rt8d4ege3,254343
我想根据第二列合并这个文件，-作为分隔符，这样结果看起来像这样：
254343,pw1jc5ssyt6hx618-pht92h4adr3mrbz3-alnac47rt8d4ege3
254333,ysezaratlycpuggl-gqjp2rsjmk1a2v9c-twdzyi2ddbnrfknd-tpqorqbyrg1nmm7s
254344,hguvgstqxu3gowfg
254341,gcmj7krrx5x6nf8r