#include <bits/stdc++.h> 
using namespace std;
using ll =long long;
#define all(v) v.begin(),v.end()
 #define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)

int main() {
  ll L,R,C;cin>>L>>R>>C;
  if(R-L<=1000) {
    ll ans=1000;
    for(ll j=L;j<=R;j++) {
ll k=C*j%1000;
if(k!=0) k=1000-k;
ans=min(ans,k);
    }

    cout<<ans<<endl;
  }
  else cout<<0<<endl;
}