import sys
input = sys.stdin.readline
mod = 998244353

l, r, c = map(int, input().split())
if r - l >= 1000:
    print(0)
else:
    ans = 10 ** 9
    for i in range(l, r+1):
        tmp = (c * i) % 1000
        if tmp:
            tmp = 1000 - tmp
        ans = min(ans, tmp)
    print(ans)