#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,n) for (int i=0;i<(int)(n);i++)

int main(){
  ll l,r,c;
  cin>>l>>r>>c;
  c%=1000;
  ll ans=1e18;
  for(ll i=l;i<=r;i++){
    ans=min(ans,((i*c+999)/1000)*1000-i*c);
    if(ans==0) break;
  }
  cout<<ans<<endl;
}