/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String[] keys = new String[]{"A", "B", "C", "D", "E"};
		String del = "";
		StringBuilder b = new StringBuilder();
		for(String key : keys){
			b.append(del).append(key);
			del = ",";
		}
		String answer = b.toString();
		System.out.printf(answer);
	}
}

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