read a b c
n=0
while((a%2+b%2+c%2==0))
do
    if((a==b&&b==c))
    then
        echo -1
        exit
    fi
    n=$((n+1))
    na=$(((b+c)/2))
    nb=$(((a+c)/2))
    nc=$(((a+b)/2))
    a=$na
    b=$nb
    c=$nc
done
echo $n
