Definition: You are provided with an arithmetic question. Your task is to compute the solution using the given arithmetic operations. The only arithmetic operators needed to answer the questions are'+'(addition) and'-'(subtraction). The answer should be correct to one decimal place.
Input: Sally had 13 peaches at her roadside fruit dish. She went to theorchard and picked peaches to stock up. There are now 55 peaches.how many did she pick?

42.0