#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using db = long double;
using ch = char;
using bl = bool;
using st = string;
using pll = pair<ll,ll>;
using psl = pair<st,ll>;
using vst = vector<st>;
using vch = vector<ch>;
using vvch = vector<vch>;
using vbl = vector<bl>;
using vvbl = vector<vbl>;
using vdb = vector<db>;
using vpll = vector<pll>;
using vpsl = vector<psl>;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vvvvi = vector<vvvi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using vvvvll = vector<vvvll>;
using vvvvvll = vector<vvvvll>;
#define all(A) A.begin(),A.end()
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define rrep(i,a,b) for(int i=(ll)(a);i<=(ll)(b);i++)

int main() {
    ll L,R,C;
    cin>>L>>R>>C;
    ll ans=2e18;
    rrep(i,L,min((ll)L+1000,R)){
        ans=min(ans,1000*((C*i+999)/1000)-C*i);
    }
    cout << ans << endl;
    return 0;
}