题解 | #挑7# 原来分段保存一下结果就行，笑死了

n = int(input())
arr = [1125, 1125, 1750, 1126, 1125, 1751, 1126, 1125, 1126, 1749]
spt = 3000
# for i in range(10):
#     ans = 0 
#     for j in range(3000):
#         x = i * 3000 + j + 1
#         if str(x).find('7') >= 0 or x % 7 == 0:
#             ans += 1
#     print(i, ans)

s = n // spt
ans = 0
for i in range(s):
    ans += arr[i]
for i in range(s * spt + 1, n + 1):
    if i == 0: continue
    if str(i).find('7') >= 0 or i % 7 == 0:
        ans += 1
print(ans)