function longestWordChain(keywords, startWord){
  var bg = keywords.sort();var kg = [];
  var now = startWord; var sk = 0;
  var same = [];

  while(1){
    kg.push(now);
    for(var i = 0;i < same.length;i++){
      if(now[now.length -1] == same[i][0]){
        if(kg.indexOf(same[i]) != -1) continue;
        else{
          now = same[i];
          sk = 1;
          break;
        }
      }
    }
    for(var i = 0;i<bg.length;i++){
      if(sk == 1){
        sk = 0;break;
      }else if(now[now.length-1] == bg[i][0]){
        if(kg.indexOf(bg[i]) == -1) continue;
        else {
        now = bg[i];break;}
      }
       else if (i==bg.length-1) {break;break}
      }
    }
    kq = kq.join("-");
    return kq;
  }