A young man asked Albert Einstein , the great German scientist , what the secret of success is. The scientist told him that the secret of success is hard work. A few days later the young man asked the same question again . Einstein was very annoyed . He did not say anything ,but wrote a few words on a piece of paper . On it was written:A=X+Y+Z. “What does this mean ?” asked the young man . “A means “success”” explained the old scientist . “X stands for hard work ,Y for good method (方法) and Z Z means stop talking and get down to work.”