与5有关的数定义为含有5或者能被5整除的数。

cnt = 0
for i in range(1,1000):
   if i % 5 == 0:
      cnt += 1
      continue
   j = i
   while j > 0:
       if j % 10 == 5:
          cnt += 1
          break
       else:
          j //= 10
print(cnt)