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.
x =int(input())
while x > 1000:
    x -= 1000
print(x)

x =int(input())
while x > 1000:
    x -= 1000
print(1000 - x)
