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)
{

    int i_characterCount;
    int matchCount = 0;
    scanf("%d", &i_characterCount);

    char c_inputString[i_characterCount];
    scanf("%s", c_inputString);

    int index = 0;
    while (index < i_characterCount)
    {
        if (c_inputString[index] == 65)
        {
            index++;
            if (c_inputString[index] == 66)
            {
                index++;
                if (c_inputString[index] == 67)
                {
                    matchCount++;
                }
            }
        }
        index++;
    }

    printf("%d", matchCount);

}