标准输出无响应

I'm doing a coding challenge and every time I submit I get a the wrong answer with a "No response on stdout" Do you know what I can do? Here is the link to the problem: https://www.hackerrank.com/challenges/counting-valleys/problem?h_l=interview&playlist_slugs%5B%5D=interview-preparation-kit&playlist_slugs%5B%5D=warmup