输入M,N，随机生成两组分别有M个，N个数据，并显示平均数，方差，再将两组数据合并，显示合并后的平均数和方差，输入insert 可以插入一个数，输入delete和序号可以删除一个数(We met at the wrong time, but separated at the right time. The most urgent is to take the most beautiful scenery; the deepest wound was the most real emotions)