fix prompt

reasoning_gym/algorithmic/base_conversion.py

@@ -6,6 +6,26 @@ from typing import Optional, Tuple
 
 from ..factory import ProceduralDataset, register_dataset
 
+QUESTION_TEMPLATE = """Your task is to convert a number between two different bases.
+
+If the target base is > 10, use lowercase letters a-z for digits above 9.
+
+Example:
+- Input: Convert the base-9 number 440 to base-5
+- Output: 2420
+- Explanation
+    - First, we convert the base-9 number 440 to base-10: 4 * 9**2 + 4 * 9**1 + 0 * 9**0 = 324 + 36 + 0 = 360
+    - Next, we convert the base-10 number 360 to base-5:
+        - 360 // 5 = 72 remainder 0
+        - 72 // 5 = 14 remainder 2
+        - 14 // 5 = 2 remainder 4
+        - 2 // 5 = 0 remainder 2
+    - Reading the remainders in reverse order gives us the base-5 number 2 4 2 0
+    - Hence, the final answer is 2420
+
+Now, convert the {source_name} number {source_repr} to {target_name}
+"""
+
 
 @dataclass
 class BaseConversionConfig:
@@ -90,11 +110,10 @@ class BaseConversionDataset(ProceduralDataset):
         source_name = self._format_base_name(source_base)
         target_name = self._format_base_name(target_base)
 
-        # Add hint for bases > 10 about using lowercase letters
-        hint = " (use lowercase letters a-z for digits above 9)" if target_base > 10 else ""
-
         return {
-            "question": f"Convert the {source_name} number {source_repr} to {target_name}{hint}",
+            "question": QUESTION_TEMPLATE.format(
+                source_name=source_name, source_repr=source_repr, target_name=target_name
+            ),
             "answer": target_repr,
             "metadata": {
                 "decimal_value": value,