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++14 (GCC 5.4.1) (judge verdict: Runtime Error)

//AnkitCode99

#include<bits/stdc++.h>

#define endl "\n"

#define ll long long int

#define MOD 1000000007

#define mp make_pair

#define pb push_back

#define vl vector

#define all(v) (v.begin(),v.end())

#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)

#define rep(i,a,b) for(long long int i=a;i<b;i++)

#define nrep(i,a,b) for(long long int i=a;i>=b;i--)

using namespace std;

int main()

{

fast;

#ifndef ONLINE_JUDGE

freopen("input.txt","r",stdin);

freopen("output.txt","w",stdout);

#endif

ll n;
cin>>n;
string s;
cin>>s;
ll c=0;
rep(i,0LL,n-3)
{
	if(s.substr(i,3)=="ABC")
		c++;
}
cout<<c<<endl;
}