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 <string.h>

int main(void){

int n,i=0,j=0,count=0,check=1;
char str[50+1];
char abc[] = "ABC"; 

scanf("%d\n%s",&n,str);

while(i <(n-2)){
   while(j <3){
   //printf("%c,%c\n",str[j+i],abc[j]);
			if (str[j+i]!=abc[j]){
				check=0;
                   //printf("%d\n",check);
                goto OUT;
			}
            j++;
        }
                   //printf("%d\n",check);
   if (check==1){
   		count++;
   }
   OUT:
   j=0;
   check=1;
	i++;
}

printf("%d",count);

return 0;
}