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.
n=int(input())
print(n%1000)
n=int(input())
s=n//1000+1
if n%1000==0:
    print(0)
else:
    print(1000*s-n)