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 (Clang 3.8.0) (judge verdict: Wrong Answer)

#include<stdio.h>
int main()
{
	char S[51];
	int N;
	scanf("%d",&N);
	int i,j=0;
	if(N>=3&&'A'<=S[i]&&S[i]<='Z')
{
		for(i=0;i<N;i++)
	{scanf("%c",&S[i]); }
	
	for(i=0;i<N;i++)
 {if(S[i]=='A'&&S[i+1]=='B'&&S[i+2]=='C')
 j++;
 }
 printf("%d",j);
}
return 0;

}