java问题class he is public, should be declared in a file named he.java，哪里出了问题？详细指出

package javaapplication20;
import java.util.Scanner;
/**
*
* @author 2333
*/
public class JavaApplication20 {

/**
* @param args the command line arguments
*/
public static void main(String[] args) {
Scanner oi=new Scanner(System.in);
int a=oi.nextInt();
int n=oi.nextInt();
int ans=a;
for(int i=0;i<n-1;i++){
ans*=a;}
System.out.print(ans);
}
}

相关了解……