1. Decision Analysis and Support Unit, SGH Warsaw School of Economics , Al. Niepodłegści 162, 02-554 Warszawa, Poland
2. Department of Mathematics, Toronto Metropolitan University , 350 Victoria St., Toronto, ON, M5B 2K3, Canada
3. Toronto Metropolitan University Department of Mathematics, , 350 Victoria St., Toronto, ON, M5B 2K3, Canada
4. Tutte Institute for Mathematics and Computing , Ottawa, ON, K1J 0B9, Canada