BEGIN{
  printf "paperID\tkeyword\n-------\t-------\n";
}
$0!~"%"{
  gsub(";",",");
  split($0,f1,".");
  paperid=f1[1];

  ileft=index($0,"{");
  if(ileft==0) next;
  iright=index($0,"}");
  if(iright==0) next;
  ileft++;
  iright--;
  keys=substr($0,ileft,iright-ileft+1);
  nkeys=split(keys,keyword,",");
  for(i=1;i<=nkeys;i++){
    j=1;
    key=keyword[i];
    while(substr(key,j,1)==" "){
      j++;
    }
    printf "%s\t%s\n", paperid,substr(key,j);
  }
}