/* -*- coding: utf-8 -*-
 *
 * 2259.cc:  No.2259 Gas Station - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

const int MOD = 1000;

/* typedef */

/* global variables */

bool used[MOD];

/* subroutines */

/* main */

int main() {
  int l, r, c;
  scanf("%d%d%d", &l, &r, &c);
  r++;

  c %= MOD;
  int lq = l / MOD, lr = l % MOD;
  int rq = r / MOD, rr = r % MOD;

  if (lq + 1 < rq)
    puts("0");
  else {
    if (lq < rq) {
      for (int i = lr; i < MOD; i++) used[i] = true;
      for (int i = 0; i < rr; i++) used[i] = true;
    }
    else
      for (int i = lr; i < rr; i++) used[i] = true;

    int minc = MOD;
    for (int i = 0; i < MOD; i++)
      if (used[i]) {
	int ci = (MOD - c * i % MOD) % MOD;
	minc = min(minc, ci);
      }

    printf("%d\n", minc);
  }
  return 0;
}