import java.util.List;
import java.util.Set;

class Matrix {

    Matrix(List<List<Integer>> values) {
        throw new UnsupportedOperationException("Delete this statement and write your own implementation.");
    }

    Set<MatrixCoordinate> getSaddlePoints() {
        throw new UnsupportedOperationException("Delete this statement and write your own implementation.");
    }
}

add starter implementation. (#1003)