"Java" Student performance management System __java Learning introductory notes

Enter the number of students:
2
Enter the number of courses:
3
Please define the 1th course:
Data structure
Define the 2nd course:
Operating system
Please define the 3 course:
Composition principle
Please enter the 1th student name:
W
Enter the W data structure score:
Group
Enter W's operating system results:
The
Please enter the composition of W:
, please enter the 2nd student name:
R
Please enter R's data structure score:
%
Enter the operating system performance of R:
$
Please enter the composition of R:
The student   data structure   operating system   composition and principle   total score   Average score   list
r          34               89           97      220     73     1th name
w          65               66          77       208      69      2nd name

Code:

public class first{public static void Main (string[] args) {Scanner in=new Scanner (system.in);
		System.out.println ("Please enter student number:");
		int Rennum=in.nextint ();
		System.out.println ("Please enter the number of courses:");
		int Cousenum=in.nextint ();
		Int[][] Arr=new Int[rennum][cousenum];
		String[] Name=new String[rennum];
		String[] Couse=new String[cousenum];
		String[] Str=new String[rennum];
		Int[] Sum=new Int[rennum];
		
		Int[] Pin=new Int[rennum];
			for (int i=0;i<couse.length;i++) {System.out.println ("please define the first" + (i+1) + "course:");
		Couse[i]=in.next ();
			for (int i=0;i<name.length;i++) {System.out.println ("Please enter the first" + (i+1) + "Student Name:");
			Name[i]=in.next (); int s=0;
			String str11= "";
				for (int j=0;j<couse.length;j++) {System.out.println ("Please enter" +name[i]+ "+couse[j]+");
				Arr[i][j]=in.nextint ();
				S+=ARR[I][J];
			str11+=arr[i][j]+ "T";
			} Sum[i]=s;pin[i]=s/cousenum;
			str[i]=name[i]+ "T" +str11+sum[i]+ "T" +pin[i];
		} System.out.print ("Student"); for (int i=0;i<cousenum;i++) SyStem.out.print ("T" +couse[i]);
		System.out.println ("\ t score \ t average score \ t list");
		/*system.out.println ();
			for (int i=0;i<rennum;i++) {System.out.print (name[i]);
			for (int j=0;j<cousenum;j++) {System.out.print ("T" +arr[i][j]);
			} System.out.print ("\ t" +sum[i]+ "T" +pin[i]);
		System.out.println (); }*/for (int i=0;i<sum.length-1;i++) {for (int j=0;j<sum.length-1;j++) {if (sum[i]<sum[j+1)) {STR
					ing T=str[i];
					STR[I]=STR[J+1];
				str[j+1]=t;
			for (int i=0;i<rennum;i++) {System.out.print (str[i]);
		System.out.println ("T" + (I+1) + "First name"); }
	}
}