OCCCN=C(S)Nc1ccc2nccnc2c1
Hydrogen bond donor is the chemical compound which contains protons to be donated. Here, protons are hydrogen atoms. The hydrogen bond donor should contain these hydrogen atoms covalently bound to itself. For example, water has two hydrogen atoms attached to the oxygen atom directly via covalent chemical bonds. Therefore, it can form hydrogen bonds with other molecules. How many hydrogen bond donor does the molecule contain?