C:\test>unionIntersect.pl -N=5e5 -MAX=27
       s/iter barvin    buk    roy   buk2
barvin   3.87     --   -28%   -40%   -50%
buk      2.80    39%     --   -17%   -30%
roy      2.33    66%    20%     --   -16%
buk2     1.95    98%    43%    19%     --