Java Arraylist got java.lang.IndexOutOfBoundsException?

Java Arraylist got java.lang.IndexOutOfBoundsException?

Hello im general 3D artist , switched from my career and start to learn
programming. I got a problem with c106a handout #5
he code work. but still got some error log here.
Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 4,
Size: 4 at java.util.ArrayList.RangeCheck(ArrayList.java:547) at
java.util.ArrayList.get(ArrayList.java:322) at
UniqueNames.showUnique(UniqueNames.java:23) at
UniqueNames.main(UniqueNames.java:39)
Why Arraylist , which can stretch capacity by it own still got an
OUTBOUNDEXCEPTION ???
heres my full code
import acm.io.*;
import acm.program.ConsoleProgram;
import acm.util.*;
import java.io.*;
import java.util.ArrayList;
import java.lang.*;
public class UniqueNames extends ConsoleProgram{
static ArrayList<String> meString = new ArrayList<String>();
static String input ;
public static void storeUnique(String input){
if (!meString.contains(input))
{
meString.add(input);
}
}
public static void showUnique(ArrayList<String> meString){
System.out.println("Unique name list contains:");
for(int i=0 ;i<= meString.size() ;i++){
System.out.println(meString.get(i));
}
}
public static void main(String[] args){
try{
InputStreamReader stream = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(stream);
while (true){
System.out.println("Enter name:");
String input = br.readLine();
if (input.equals("")) break;
storeUnique(input);
}
{showUnique(meString);}
}
catch(IOException e){
}
}
}