/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.stream.*;
import java.util.function.*;
 
 
/* 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
	{
		Stream<String> ss = Arrays.stream(new String[] {"a,b,c","a,c,d","d,b,c"});
 
		Map<String,Integer> fm = ss
		    .map(line -> line.split(","))
		    .flatMap(Arrays::stream)
		    .map(String::trim)
            .collect(Collectors.groupingBy(Function.identity(), Collectors.summingInt(e -> 1)));
        for (Map.Entry<String,Integer> e : fm.entrySet()) {
        	System.out.println(e.getKey()+" "+e.getValue());
        }
	}
}

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YSxiLGMsZCwKZSxhLGIsZCwKYixiLGMsZCxh

a,b,c,d,
e,a,b,d,
b,b,c,d,a