Notes

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.*;

class Test1_2 {

static final int DENOMINATION_MULTIPLIER = 100;
public static void main(String[] args) {
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(isr);

try {
String input = br.readLine();
String[] ip = input.split(";");
double PP = Double.parseDouble(ip[0]);
double CP = Double.parseDouble(ip[1]);

// double PP = Double.parseDouble(br.readLine());
// double CP = Double.parseDouble(br.readLine());
calculateChange(PP, CP);
} catch(Exception e) {
System.out.println(e);
}
}

private static void calculateChange(double PP, double CH) {
double changeDiff = CH - PP;

if (changeDiff < 0) {
System.out.println("ERROR");
} else if (changeDiff == 0) {
System.out.println("ZERO");
} else {
LinkedHashMap<Double, String> map = new LinkedHashMap<>();
Money registerMoney = new Money();
map = registerMoney.getCashDenomination();

System.out.println(calculateChange(map,changeDiff));
}
}

private static String calculateChange(LinkedHashMap<Double,String> denominations, Double change) {
change = change * DENOMINATION_MULTIPLIER;

// LinkedHashMap<Double, String> demonimations = new LinkedHashMap<>();
// Money registerMoney = new Money();
// demonimations = registerMoney.getCashDenomination();

StringBuilder sb = new StringBuilder();

Iterator<Map.Entry<Double, String>> iterator = denominations.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry<Double, String> entry = iterator.next();
double mapDenomValue = entry.getKey() * DENOMINATION_MULTIPLIER;
String denomDescription = entry.getValue();
while (change >= mapDenomValue) {
change -= mapDenomValue;
sb.append(denomDescription);
sb.append(",");
}
}

String st = sb.toString();
return st.substring(0, st.length() - 1);
}
}

class Money {
private LinkedHashMap<Double,String> map;
Money(){
map = new LinkedHashMap<Double,String>();
populateCashDenomination();
}

private void populateCashDenomination() {
map.put(50.0, "Fifty Pounds");
map.put(20.0, "Twenty Pounds");
map.put(10.0, "Ten Pounds");
map.put(5.0, "Five Pounds");
map.put(2.0, "Two Pounds");
map.put(1.0, "One Pound");

map.put(0.5, "Fifty Pence");
map.put(0.2, "Twenty Pence");
map.put(0.1, "Ten Pence");
map.put(0.05, "Five Pence");
map.put(0.02, "Two Pence");
map.put(0.01, "One Pence"); }

public LinkedHashMap<Double,String> getCashDenomination() {
return map;
}
}