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: Accepted)

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char te[] = "ABC";
int main()
{
	char *s;
	int i,count,n,flag,j;
	
	count = 0;
	scanf("%d",&n);
	
	getchar();
	
	s = malloc(sizeof(char) * n);
	
	gets(s);
	
	for(i = 0;*(s + i);)
	{
		if(*(s + i) == te[0])
		{
			flag = 1;
			for(j = 1;te[j];j++)
			{
				if(te[j] != *(s + i + j))
				{
					flag = 0;
					break;
				}
			}
			if(flag == 1)
				count++;
				
			i++;
		}
		else i++;
	}
	
	printf("%d\n",count);
	
	return 0;
}