题解 | #HJ055 挑7#

import java.util.Scanner;

/**
 * HJ55 挑7 - 中等
 */
public class HJ055 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            int num = sc.nextInt();
            int n = 0;
            for (int i = 7; i <= num; i++) {
                String str = String.valueOf(i);
                if (i % 7 == 0 || str.contains("7")) {
                    n++;
                }
            }
            System.out.println(n);
        }
        sc.close();
    }
}