activezerosmarkcons0zerosactiveandttXmarkXactivelengthnilmark0activelengthconsNLmarkslengthLmarkzerosactivezerosmarkconsX1X2activeconsmarkX1X2mark0active0markandX1X2activeandmarkX1X2markttactivettmarklengthXactivelengthmarkXmarknilactivenilmarksXactivesmarkXconsmarkX1X2consX1X2consX1markX2consX1X2consactiveX1X2consX1X2consX1activeX2consX1X2andmarkX1X2andX1X2andX1markX2andX1X2andactiveX1X2andX1X2andX1activeX2andX1X2lengthmarkXlengthXlengthactiveXlengthXsmarkXsXsactiveXsX