s = input()
r_cnt = 0
b_cnt = 0
for color in s:
  if color == 'R':
    r_cnt += 1
    if r_cnt > (s.length/2):
      print('Yes')
      break
  else:
    b_cnt += 1
    if b_cnt > (s.length/2):
      print('No')
      break



 

 