/*
 * Copyright 2017 haeun kim
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package algorithm.boj;

import java.io.*;

/**
 * Created by haeun on 2017-09-29
 * Site       : https://www.acmicpc.net/problem/1065
 */

public class Boj1065 {

    public static void main(String[] args) throws IOException {
         BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
         int n = Integer.parseInt(br.readLine());
         int count = 0;

         if(n < 100){
             System.out.println(n);
         }else{
             for(int i=100; i<=n; i++){
                 if(i/100 - (i%100)/10 == (i%100)/10 - i%10){
                     count++;
                 }
             }
             System.out.println(count+99);
         }
    }

}

Solve No.1065 from Baekjoon Online Judge