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: Wrong Answer)

#include<iostream>
using namespace std;
int main()
{
  int l,c=0;
  char a[l];
  cin>>l;
  for(int i=0;i<l;i++)
    cin>>a[i];
  for(int i=0;i<l-3;i++)
  {
    if((int)a[i]==65 && (int)a[i+1]==66 && (int)a[i+2]==67)
    {  cout<<"Yes"<<endl;
       c=1;
     break;}
  }
  if(c==0)
    cout<<"No";
  return 0;
}