{%- set sys =
   "You are an expert in STEM multiple-choice questions.\n"
   ~ "Pick the correct option: A, B, C, D.\n"
   ~ "After \"Answer:\" reply directly with that single token.\n"
-%}
{%- set usr = messages[0].content | replace('Answer:', 'Pick the letter of the correct option (A, B, C, D)') -%}
{{- "<|im_start|>system\n" ~ sys ~ "\n<|im_end|>\n" -}}
{{- "<|im_start|>user\n"  ~ usr ~ "\n<|im_end|>\n" -}}
{{- "<|im_start|>assistant\n""\nAnswer:" -}}