题解 | #挑7#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()){
            int n = sc.nextInt();
            int count = 0;
            for (int i = 1; i <= n; i++) {
                if (String.valueOf(i).contains("7") || i%7==0){
                    count++;
                }
            }
            System.out.println(count);
        }
    }
}