题目

B      Among all the fast growing science and technology, the research of human genes, or biological engineering as people call it, is drawing more and more attention now. Sometimes it’s a hot topic discussed by people.      The greatest thing that gene technology can do is to cure serious diseases that doctors at present can almost do nothing with, such as cancer and heart disease. Every year, millions of people are murdered by these two killers. And to date, doctors have not found an effective way to cure them. But if the gene technology is applied, not only these two diseases can  与的积为正整数的数是____________（写出一个即可）