Problem:
Score : 300 points

Problem Statement

There are N slimes lining up from left to right. The colors of these slimes will be given as a string S of length N consisting of lowercase English letters. The i-th slime from the left has the color that corresponds to the i-th character of S.

Adjacent slimes with the same color will fuse into one larger slime without changing the color. If there were a slime adjacent to this group of slimes before fusion, that slime is now adjacent to the new larger slime.

Ultimately, how many slimes will be there?

Constraints

1 \leq N \leq 10^5

|S| = N

S consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

N
S

Output

Print the final number of slimes.

Sample Input 1

10
aabbbbaaca

Sample Output 1

5

Ultimately, these slimes will fuse into abaca.

Sample Input 2

5
aaaaa

Sample Output 2

1

All the slimes will fuse into one.

Sample Input 3

20
xxzaffeeeeddfkkkkllq

Sample Output 3

10

Solution in Common Lisp (SBCL 1.1.14) (judge verdict: Accepted)

(defun solve (n s)
  (let ((i 0)
        (count 0))
    (loop
      (when (<= n i)
        (return count))
      (let ((char (aref s i)))
        (incf count)
        (loop for j from (1+ i) below n
              while (char= char (aref s j))
              finally (setf i j))))))

#-swank
(let* ((n (read))
       (s (read-line)))
  (format t "~A~%" (solve n s)))