镜像数字

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int r = 0;
        for(int i = 1; i <= N; ++i) r += f(i);
        System.out.println(r);
    }
    public static int f(int n){
        String[] v = {"0", "1", "5", "", "", "2", "9", "", "8", "6"};
        String N = String.valueOf(n);//把原数字当成字符串处理，避免除法和取余
        StringBuilder sb = new StringBuilder();
        for(int i = 0; i < N.length(); ++i) sb.append(v[N.charAt(i) - '0']);
        if(sb.length() != N.length()) return 0;//变短了，肯定有347
        if(Integer.valueOf(String.valueOf(sb)) != n) return 1;
        return 0;
    }
}