 First, we con-sider the movements of susceptible (S), exposed (E), and recovered (R) people as well as infected (I) who can get infected after movement .
<clarity>  First, we con-sider the movements of susceptible (S), exposed (E), and recovered (R) people as well as infected (I) who can get infected after movement .
 First, we con-sider the movements of susceptible (S), exposed (E), and recovered (R) people as well as infected (I) .