/* 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 String randomizeCase(String str) {
 
    Random rnd = new Random();
    StringBuilder sb = new StringBuilder(str.length());
 
    for (char c : str.toCharArray())
        sb.append(rnd.nextBoolean()
                      ? Character.toLowerCase(c)
                      : Character.toUpperCase(c));
 
    return sb.toString();
}
 
	public static void main (String[] args) throws java.lang.Exception
	{
		System.out.println(randomizeCase("hello world"));
	}
}

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