R t 2

R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2R t 2