题解 | #挑7#

import sys
while True:
    try:
        N = int(input()) + 1
        count = 0
        for i in range(1,N):
            #直接判断是否整除7或者包含7
            if i % 7 == 0 or '7' in str(i):
                count += 1
        print(count)

    except:
        break