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(19, mostFrequentPrime(Arrays.asList(Arrays.asList(1,1),Arrays.asList(9,9),Arrays.asList(1,1))));
}
@Test
public void test2() {
    assertEquals(-1, mostFrequentPrime(Arrays.asList(Arrays.asList(7))));
}
@Test
public void test3() {
    assertEquals(97, mostFrequentPrime(Arrays.asList(Arrays.asList(9,7,8),Arrays.asList(4,6,5),Arrays.asList(2,8,6))));
}

}