Complete the story by one sentence …

Once there was an old man. He had four sons. They always quarreled with one another. One fine day he decided to teach them a lesson. He called all his room. As they came and sat in his room. He said to them, "Today I am going to teach you a very important lesson of life. Pay heed to it. There is a bundle of sticks lying in the corner, and I want each one of you to try to break it." All the four sons tried to break it one by one. But no one of them could do it. After all the sons had tried their best and given up, he asked his eldest son, "Now, open the bundle and separate the sticks and try to break them. " Quite easily, each of the four sons broke the sticks easily. The old man said. "Did you see when the stick were bound together, nobody could break them; however, when they were separated, each stick could be easily broken. Similarly, if you remain united like the bundle, no one will be able to break you. But if you fight and live separately, you will be easily broken." The sons understood the lesson. They decided never to fight with one another. They had learnt that unity is strength.