import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
 
public class Main {
    public static void main(String[] args) throws IOException{
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        String q = bufferedReader.readLine();
        int k = Integer.parseInt(q);
        String s = bufferedReader.readLine();
        int l, r, flag=0, ans=0;
		for(int i=0; i<s.length()-k+1; i++)
		{
			flag=0;
			l=i;
			r=i+k-1;
			for(int j=0; j<k/2; j++)
			{
			    if(s.charAt(l+j)!=s.charAt(r-j)){ 
			        flag=1;
			        break;
			    }
			}
			if(flag==0){
			    ans++;
			}
		}
		System.out.print(ans);
    }
}

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MwpiYWJjYmFi

3
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