ive just been using that kind of idea

one way is to......
set up 13 up cariables and 13 down variables
up1....up13
dn1....dn13

set all 13 up to 0 and all down to 0 before reading the indicators

now as each one is true set it to 1
if up1 + up2=up3+up4=up5+up6+...up13==10
then you have 10 out of the 13 true
and viki verki for the downs