实验二：编写一个MyMath类,具有low、high两个整数属性,添加两个构造方法,一个带一个整数参数,用于设置high

class MyMath {
int low,high;
MyMath(int h) { this(1,h); }
MyMath(int l,int h) { low = l; high = h; }
int sum() { return (low + high) * (high - low + 1) / 2; }
int product() {
int p = 1;
for (int x = low; x