[백준] 14912번 숫자 빈도수 (silver 5

import java.io.*;
import java.util.*;

public class Main{
    public static void main(String[] args) throws IOException{
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));
        StringTokenizer st=new StringTokenizer(br.readLine());
        int n=Integer.parseInt(st.nextToken());
        int find=Integer.parseInt(st.nextToken());
        int answer=0;
        for(int i=1; i<=n; i++){
            String a=String.valueOf(i);
            for(int j=0; j<a.length(); j++){
                if(a.charAt(j)-'0'==find){
                    answer++;
                }
            }
        }
        bw.write(answer+"");
        bw.flush();
    }
}