There are *n* stones on the table in a row, each of them can be red, green or blue. Count the minimum number of stones to take from the table so that any two neighboring stones had different colors. Stones in a row are considered neighboring if there are no other stones between them.
The first line contains integer *n* (1 ≤ *n* ≤ 50) — the number of stones on the table. 

The next line contains string *s*, which represents the colors of the stones. We'll consider the stones in the row numbered from 1 to *n* from left to right. Then the *i*-th character *s* equals "R", if the *i*-th stone is red, "G", if it's green and "B", if it's blue.
#initializes numbers and inputs
n = int(input())
s = list(input())
rocksTaken = 0
rockNumber = 0

#for every rock in string, counts how many match prior rock and removes them
for rock in range(n):
  if rockNumber == 0: #skips 1st rock
    rockNumber +=1
    continue
  else:
    if s[rockNumber] == s[rockNumber - 1]:
      s.remove(s[rockNumber])
      rocksTaken += 1
      print(s)
    else:
      rockNumber += 1
      print(s)
    
#prints number of rocks taken
print(rocksTaken)