p1024.purgetask.purged.gzfile contains the matrix output by the purge step of CADO-NFS (input of the merge step).
p1024.purgetask.purged.gz file contains a matrix defined
over GF(q), where q=1120320311183071261988433674300182306029096710473,
with 95928630 rows and
95928627 columns, where the column indices go from 0 to 210182983.
After a header line containing that information, each row is encoded by one
a,b: followed by a list of hexadecimal numbers
from 0 to 210182983 for the column indices for that row.