Problem:
Score : 200 points

Problem Statement

We have a string S of length N consisting of uppercase English letters.

How many times does ABC occur in S as contiguous subsequences (see Sample Inputs and Outputs)?

Constraints

3 \leq N \leq 50

S consists of uppercase English letters.

Input

Input is given from Standard Input in the following format:

N
S

Output

Print number of occurrences of ABC in S as contiguous subsequences.

Sample Input 1

10
ZABCDBABCQ

Sample Output 1

2

Two contiguous subsequences of S are equal to ABC: the 2-nd through 4-th characters, and the 7-th through 9-th characters.

Sample Input 2

19
THREEONEFOURONEFIVE

Sample Output 2

0

No contiguous subsequences of S are equal to ABC.

Sample Input 3

33
ABCCABCBABCCABACBCBBABCBCBCBCABCB

Sample Output 3

5

Solution in PHP7 (7.0.15) (judge verdict: Accepted)

   <?php 
     $n = trim(fgets(STDIN));
     $s = str_split(trim(fgets(STDIN)));
     $ans = 0;
     for($i = 0; $i < $n; $i++){
       if($s[$i] == "A"){
           if($s[$i+1] == "B" && $s[$i+2] == "C"){
             $ans++;
           }
       }else{
         continue;
       }
     }
     echo $ans;
    ?>