A mouse walks on a plane. At time $i$, it could do nothing or turn right, then it moves $p_i$ meters forward, where $p_i$ is the $i$-th prime. Is it possible that the mouse moves back to the starting point?
Source: IMOC 2017 N6
Tags: number theory
A mouse walks on a plane. At time $i$, it could do nothing or turn right, then it moves $p_i$ meters forward, where $p_i$ is the $i$-th prime. Is it possible that the mouse moves back to the starting point?