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()
{
    int i,len,con=0,count=0;
    char a[100];
    scanf("%d",&len);
    getchar();
    for(i=0;i<len;i++)
    {
        scanf("%c",&a[i]);
        if(a[i]=='A')
            con=1;
        else if(a[i]=='B'&&con==1)
            con++;
        else if(a[i]=='C'&&con==2)
            con++;
        else
            con=0;
        if(con==3)
        {
            count++;
            con=0;
        }
    }
    printf("%d",count);
    return 0;
}