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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>
int main(void)
{
	char str[60], abc[5] = {"ABC"};
	int n = 0,count = 0,ans = 0;
	scanf("%d", &n);
	for (int i = 0; i < n; i++) {
		scanf("%c", &str[i]);
	}

	for (int i = 0; i < n; i++) {
		if (str[i] == abc[count]) {
			count++;
		}
		else {
			count = 0;
		}

		if (count >= 3) {
			count = 0;
			ans++;
		}
	}

	printf("%d\n", ans);

	return 0;
}