$"=",";@0=sort{$a<=>$b}split/,/,'1089,3,4,5,6,7,99,832,1087,831,1088';$_=
":@0";1while s;:((\d+)(-(\d+))?),(\d+);$4?$5-$4==1?":$2-$5":",$1:$5":($5-
$2==1)?":$2-$5":",$2:$5";e;y/:/,/d;s/^.//;print;