what does 5x3r for wrist walks, first knuckle etc mean

I'm confused about what the 5x2r, 5x3r really means. The videos haven't ever changed and I've just been following exactly what the videos show since it was 1x2r. U understand that the first number is the sets but the 2r, 3r is confusing. does 2r for wrist walks mean I go, right down, left down, left up, right up twice? then 3r is this process three times? Thanks in advance. 

HI Rodrigo in order to be more accurate:

-when you are working one arm /wrist at time. one rep consist of begin a movement (bottom position), move along the rom to reach the middle position (top position and then move back to the starting position. 

for example 3x2 r mean . 

first set  2 reps of  (starting position, up, down to starting position)

second set 2 reps of (starting position, up, down to starting position)

third set 2 reps of (starting position, up, down to starting position)

all of this must be done for both the hands separately

-when you work with both wrists like knuckle push up and you have to perform 3x2rep it will be

3 set of :

2 reps of (starting position, up, down to starting position).  reps are performed simultaneously.