month │ Jan │ Feb │ Mar │ Apr │ May │ Jun │
──────────────────────────────────
surplus/deficit │+2000 │+3000 │-3500 │+1500 │-6000 │+2500 │
更新1:
(a) Which month did he spend the least and what was the amount? (b) Which month did he spend the most and want was the amount?