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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;

public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        // 整数の入力
        int N = sc.nextInt();
        String S = sc.next();
        int count = 0;

        for(int i=0; i<N; i++){
            if(i+2 == N){
                break;
            }
            if(S.charAt(i)=='A'){
                if(S.charAt(i+1)=='B'){
                    if(S.charAt(i+2)=='C'){
                        count++;
                    }
                    else{
                        continue;
                    }
                }
                else{
                    continue;
                }
            }else{
                continue;
            }
        }
        // 出力
        System.out.println(count);
    }
}