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

    @Test
public void test1() {
    assertEquals(15, matrixSum(new ArrayList<>(Arrays.asList(new ArrayList<>(Arrays.asList(7,2,1)),new ArrayList<>(Arrays.asList(6,4,2)),new ArrayList<>(Arrays.asList(6,5,3)),new ArrayList<>(Arrays.asList(3,2,1))))));
}
@Test
public void test2() {
    assertEquals(1, matrixSum(new ArrayList<>(Arrays.asList(new ArrayList<>(Arrays.asList(1))))));
}

}