What poems can encourage children who fail the exam?

The edge of the sword comes from sharpening, and the fragrance of plum blossoms comes from bitter cold. I think this classic poem can greatly encourage those children who failed in the exam, because this sentence itself describes a truth, only if you persevere, only if you work hard, you will eventually succeed, so we should encourage those children who failed in the exam, don't criticize them, but tell them that you have worked hard and you will eventually succeed.