import java.util.*;
import java.lang.*;

class Main {
    public static void main (String[] args)  {
        Scanner scanner = new Scanner(System.in);
        int N = scanner.nextInt();
        String S = scanner.next();
        int numOccurences = 0;
        for (int i=0;i<N;i++){
            if (S.charAt(i)=='A'&&(i+2)<N){
                if (S.charAt(i+1)=='B'&&S.charAt(i+2)=='C'){
                    numOccurences++;
                }
            }
        }
        System.out.println(numOccurences);
    }
}


/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz