20250120 finished.

src/problem/mod.rs

@@ -442,3 +442,5 @@ mod p3097_shortest_subarray_with_or_at_least_k_ii;
 mod p3287_find_the_maximum_sequence_value_of_array;
 
 mod p2266_count_number_of_texts;
+
+mod p2239_find_closest_number_to_zero;