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 Java (OpenJDK 1.8.0) (judge verdict: Runtime Error)

import java.util.Scanner;

public class Main{
	public static void main(String[] args)throws Exception {
		Scanner scan = new Scanner(System.in);
		String str = scan.next();
		int cnt = 0;
		String[] array = new String[str.length()];
		for(int i = 0;i < str.length();i++) {
			array[i] = Integer.toString(str.charAt(i+1));
		}
		for(int i = 0;i < -2 + str.length();i++) {
			if(array[i].equals("B") && array[i+1].equals("B") && array[i+2].equals("C")) {
				cnt++;
			}
		}
		System.out.println(cnt);
		
		scan.close();
	}
}