solution.js

const solution = (message, length) => {
  const words = message.split(' ');

  const filteredMessages = [];
  let flag = true;

  for (let word of words) {
    if (word.length > length) {
      flag = false;
      break;
    }

    if (
      filteredMessages.length !== 0 &&
      filteredMessages[filteredMessages.length - 1].length + word.length <
        length
    ) {
      const newMessage = filteredMessages[filteredMessages.length - 1].concat(
        ' '.concat(word)
      );
      filteredMessages.splice(filteredMessages.length - 1, 1, newMessage);
    } else {
      filteredMessages.push(word);
    }
  }

  return flag ? filteredMessages.length : -1;
};