function open(rowIndex, cellIndex) { 
  (중략)

  if (openCount === row * cell - mine) {
    const time = (new Date() - startTime) / 1000;
    clearInterval(interval);
    $tbody.removeEventListener('contextmenu', onRightClick);
    $tbody.removeEventListener('click', onLeftClick);
    setTimeout(() => {
      alert(`승리했습니다! ${time}초가 걸렸습니다.`);
    }, 0);
  }

  return count;
}
(중략)
function onLeftClick(event) {
  (중략)
  } else if (cellData === CODE.MINE) { // 지뢰 칸이면
    target.textContent = '펑';
    target.className = 'opened';

    clearInterval(interval);

    $tbody.removeEventListener('contextmenu', onRightClick);
    $tbody.removeEventListener('click', onLeftClick);
  } // 나머지는 무시
}