<oerjan> le/rn speedy gonzales/Sp e e d y G o n z a l e s i s t h e f a s t e s t m o

#!/bin/sh
count () {
    hg log --template '{desc}\n' |
    egrep '<[^]]*> karma\'$1 |
    fgrep -vix "<$2> karma$1 $2" |
    cut -d' ' -f3 |
    fgrep -cix "$2"
}
plus=$(count + "$1")
minus=$(count - "$1")
echo $(($plus-$minus))