import java.util.*;
import java.lang.*;
 
class Main
{
    public static void main (String[] args) throws java.lang.Exception
	{
		List<Class<? extends Filter>> filters = new ArrayList<Class<? extends Filter>>();
        filters.add(FooFilter.class);
        filters.add(BarFilter.class);
        System.out.println(filters.size());
	}
 
    private class Filter {}
    private class FooFilter extends Filter {}
    private class BarFilter extends Filter {}
}

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