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 11.0.6) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {
	
	public static void countABC(char[] arr) {
		int counter = 0;
		for (int count = 0; count < arr.length - 2; count++) {
			if(arr[count] == 'A' && arr[count + 1] == 'B' &&
				arr[count + 2] == 'C') counter++;
		}
		System.out.println(counter);
	}

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		scan.nextInt();
		countABC(scan.next().toCharArray());
		scan.close();
	}

}