import static org.junit.jupiter.api.Assertions.*;
import org.junit.jupiter.api.Test;
import java.util.List;
import java.util.Arrays;
public class Main {
    //Program start

    //Program end

    @Test
public void test1() {
    assertEquals("aabcbbca", lastNonEmptyString("aabcbbca"));
}
@Test
public void test2() {
    assertEquals("abcd", lastNonEmptyString("abcd"));
}

}