java初学者自己编的成绩查询程序

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class chengji {

/**
 * @param args
 */
public static void main(String[] args) throws IOException{
// TODO Auto-generated method stub
BufferedReader Reader=new BufferedReader(new InputStreamReader(System.in));
    int grade=6;
    int gride=5;
    int person=50;int i,j,k;
    
    int[][][] point=new int[grade][gride][person];
    
    for (i=0;i<grade;i++)
    {
     for(j=0;j<gride;j++)
     {
     for(k=0;k<person;k++)
     {
      point[i][j][k]=(int)(Math.random()*100+0.5);
     }
     }
    }
    String goon="是";
    do{