import java.math.BigInteger;
import java.util.Arrays;

/**
 * @author Soap
 * time 2021年8月10日 10:41 上午
 */
public class test {
 public static void main(String[] args) {
// Solution s = new Solution();
 Father father1 = new Father(30);
// Son son1 = new Father(22); //报错,父类无法转化为子类。
 Father father2 = new Son(18, "xiaoming"); //子类转换成父类,自有变量会被隐藏
 System.out.println();
 }
}


class Solution {

 public int minNonZeroProduct(int p) {
 return BigInteger.valueOf((1L << p) - 2).modPow(BigInteger.valueOf((1L << p - 1) - 1), BigInteger.valueOf(1000000007))
 .multiply(BigInteger.valueOf((1L << p) - 1)).mod(BigInteger.valueOf(1000000007)).intValue();
 }
}

class Father {
 public int age;

 Father(int age) {
 this.age = age;
 }
}

class Son extends Father {
 public String name;

 Son(int age) {
 super(age);
 this.name = "liming";
 }

 Son(int age, String name) {
 super(age);
 this.name = name;
 }
}