// your code goes here
let tokens = ["a", "a", "to", "b", "c"];
let pos = tokens.findIndex(e => (e === "to"));
print(pos);
      let lists = [];
      if (pos >= 0) {
        pos++;
        while (pos < tokens.length() && tokens[pos].search("@") === 0) {
          print(pos);
          lists.push(tokens[pos]);
        }
      }
      print(lists);
      if (lists.length() === 0) {
        lists.push("@default");
      } else {
        tokens.splice(pos - lists.length() - 1, pos);
      }

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