User: I have a question about the chemical with SMILES CC(C)OC(=O)OCOP(=O)(CO[C@H](C)Cn1cnc2c(N)ncnc21)OCOC(=O)OC(C)C.O=C(O)/C=C/C(=O)O.
Assistant: How can I help?
User: What is the definition of this compound's USAN stem?
Assistant: The answer is antivirals
User: I have a question about the {#molecule|chemical|compound!} with {SMILES__description} {SMILES#}.
Assistant: {#Sure, what is your question?|How can I help?|That sounds interesting, how can I help?|Interesting, how can I help?!}
User: {quest#}
Assistant: {#The answer is |!}{answ#}
CC(C)OC(=O)OCOP(=O)(CO[C@H](C)Cn1cnc2c(N)ncnc21)OCOC(=O)OC(C)C.O=C(O)/C=C/C(=O)O
CC(C)OC(=O)OCOP(=O)(CO[C@H](C)Cn1cnc2c(N)ncnc21)OCOC(=O)OC(C)C.O=C(O)/C=C/C(=O)O
[[(2R)-1-(6-aminopurin-9-yl)propan-2-yl]oxymethyl-(propan-2-yloxycarbonyloxymethoxy)phosphoryl]oxymethyl propan-2-yl carbonate;(E)-but-2-enedioic acid
What is the definition of this compound's USAN stem?