1. Stern College for Women, Yeshiva University 1 , 245 Lexington Ave., New York, New York 10016, USA
2. Courant Institute of Mathematical Sciences at NYU 2 , 251 Mercer Street, New York, New York 10012, USA
3. Department of Computer Science, Columbia University 3 , 500 W. 120th Street, New York, New York 10027, USA
4. Department of Applied Mathematics, Kaunas University of Technology 4 , Studentu 50-429, 51368 Kaunas, Lithuania