$ cat LowGrades.java 
import java.io.InputStream;
import java.io.PrintStream;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Scanner;
import java.util.Vector;

class
LowGrades {

  private static Map<String, Triple>
  in(Iterator<Triple> triples) {

    final HashMap<String, Triple> lowGrades = new HashMap<String, Triple>();

    while (triples.hasNext()) {
      final Triple t = triples.next();
      
      if (   !lowGrades.containsKey(t.course)
       || lowGrades.get(t.course).studentID > t.studentID)
   lowGrades.put(t.course, t);
      }

    return lowGrades;
    }


  public static void
  main(String[] args) {
    out(System.out, in(new TripleIterator(System.in)));
    }


  private static void
  out(PrintStream outs, Map<String, Triple> lowGrades) {
    
    final Vector<String> keys = new Vector<String>(lowGrades.keySet());
    Collections.sort(keys);
    
    for (String key : keys)
      outs.printf("%s %d%n", key, lowGrades.get(key).grade);
    }


  private static class
  Triple {

    final int studentID;
    final String course;
    final int grade;

    Triple(int s, String c, int g) {
      studentID = s;
      course = c;
      grade = g;
      }
    }  


  private static class
  TripleIterator
  implements Iterator<Triple> {

    public boolean
    hasNext() {
      return scanner.hasNextInt();
      }

    TripleIterator(InputStream ins) {
      scanner = new Scanner(ins);
      scanner.useDelimiter("[|\n]");
      }

    public Triple
    next() {
      return new Triple(scanner.nextInt(), scanner.next(), scanner.nextInt());
      }

    private final Scanner scanner;
    }
  }


$ javac -Xlint LowGrades.java 

$ cat <<eot | java LowGrades
> 22|Math|45
> 23|English|52
> 22|English|51
> 26|Math|72
> 23|Math|61
> 21|English|81
> eot
English 81
Math 45

$ echo this is a test | ./LowGradesData
14|this|14
20|a|20
4|this|4
22|a|22
26|test|26
17|is|17
2|is|2
1|a|1
26|test|26
28|a|28
20|is|20
13|test|13
10|a|10
4|test|4
16|is|16
12|is|12
8|test|8
6|this|6
3|is|3
18|test|18
7|test|7
11|is|11
15|this|15
12|a|12

$ echo lost my shape trying to act casual | ./LowGradesData | java LowGrades
act 3
casual 6
lost 4
my 2
shape 5
to 2
trying 6

$