We will buy a product for N yen (the currency of Japan) at a shop.  If we use only 1000-yen bills to pay the price, how much change will we receive?  Assume we use the minimum number of bills required.
import math
N = int(input())
print(int(math.ceil(N / 1000) * 1000))
import math
N = int(input())
print(int(math.ceil(N / 1000) * 1000) - N)

