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