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: Accepted)

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define fastread() (ios_base:: sync_with_stdio(false),cin.tie(NULL))
#define fi first
#define se second
#define pb push_back
#define eb emplace_back

int main()
{
    fastread();


    ll n;
    cin>>n;


    string str;

    cin>>str;


    ll cnt=0,a=0,b=0,c=0;

    for(ll i=2;str[i];i++)
    {
        if(str[i-2]=='A'  and str[i-1]=='B' and str[i]=='C')
        {
            cnt++;
            i++;
            i++;
        }


    }

    cout<<cnt<<endl;


}