X=input().split()
L=int(X[0])
R=int(X[1])
C=int(X[2])
t=1000
a=t
b=(L*C)%t
while L<=R:
	if b==0:
		print(0)
		exit(0)
	a=min(a,t-b)
	b=(b+C)%t
	L+=1
print(a)