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>

int main(void){
    int N;
    char S[51];
    char A[] = {"ABC"};
    //printf("%s\n",A);
    int count=0;
    scanf("%d %s",&N,S);
    for(int i=0; i<=N-3; i++){
        for(int j=0; j<3; j++){
            //printf("i=%d j=%d S[i+j]=%c A[j]=%c\n",i,j,S[i+j],A[j]);
            if(S[i+j] == A[j]){
                if(j==2) count++;
            }else{
                break;
            }
        }
    }
    printf("%d",count);
}