public class Test {
    public static void main(String[] args) {
        List<Class<? extends A>> list = new ArrayList<Class<? extends A>>();
        list.add(A.class);
        list.add(C.class);
        list.add(B.class);
        Class<? extends A> cls = findOuterClass(list);
        System.out.println(cls);
    }

    public static <T> Class<? extends T> findOuterClass(List<Class<? extends T>> list) {
        if (list == null || list.size() == 0)
            return null;

        Class<? extends T> outerClass = list.get(0);
        for (int i=0; i<list.size(); ) {
            try {
                Class<? extends T> cls = list.get(i);
                cls = outerClass.asSubclass(cls);
                i++;
            } catch (Exception e) {
                outerClass = list.get(i);
            }
        }
        return outerClass;
    }
}

class A {

}

class B extends A {

}

class C extends B {

}