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: Nancy found 35 seashells and 25 starfish on the beach. She gave 17of the seashells to Jason. How many seashells does Nancy now have?

18.0