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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"fmt"
)

func main() {

	// 読み込み数取得
	var n int
	var s string
	fmt.Scan(&n, &s)

	count := 0

	for i := 0; i < (n - 2); i++ {
		if s[i:(i+3)] == "ABC" {
			count++
		}
	}
	fmt.Printf("%d\n", count)

}