{%- set sys = 
   "You are an expert in advanced master-level STEM multiple-choice questions.\n"
   ~ "When given a question with choices A through D:\n"
   ~ "1. Do NOT output any chain-of-thought or explanation.\n"
   ~ "2. ONLY output exactly one of these four tokens (including the leading space): \" A\", \" B\", \" C\", or \" D\".\n"
   ~ "3. Do not add any punctuation or extra text before or after."
-%}
{%- set usr = messages[0].content | replace('Answer:', '') -%}
{{- "<|im_start|>system\n" ~ sys ~ "\n<|im_end|>\n" -}}
{{- "<|im_start|>user\n"  ~ usr ~ "\n<|im_end|>\n" -}}
{{- "<|im_start|>assistant\n""\nAnswer:" -}}