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 9.2.1) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <string.h>
int main(void) {
  char s[51];
  int n;
  int count = 0;
  int subCnt = 0;
  scanf("%d", &n);
  scanf("%s", s);
  for(int i = 0; s[i] != '\0'; i++) {
    if(s[i] == 'A') {
      subCnt++;
    } else if(s[i] == 'B' && subCnt == 1) {
      subCnt++;
    } else if(s[i] == 'C' && subCnt == 2) {
      count++;
      subCnt = 0;
    } else {
      subCnt = 0;
    }
  }
  printf("%d", count);
  return 0;
}