#include <bits/stdc++.h>
#include <atcoder/all>

#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

using namespace std;
using namespace atcoder;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define repll(i, n) for (long long i = 0; i < (long long)(n); i++)
#define rep2(i, n, m) for (int i = n; i < (int)(m); i++)
#define repll2(i, n, m) for (long long i = n; i < (long long)(m); i++)
#define all(v) v.begin(),v.end()
using ll=long long;
using ld=long double;
using vi=vector<int>;
using vvi=vector<vi>;
using vvvi=vector<vvi>;
using vl=vector<ll>;
using vvl=vector<vl>;
using vvvl=vector<vvl>;
using vld=vector<ld>;
using vvld=vector<vld>;

int dx[8]={1,0,-1,0,1,1,-1,-1};
int dy[8]={0,1,0,-1,1,-1,1,-1};

const double PI = acos(-1);
//const ll MOD=1e9+7;
//const ll MOD=998244353;
const ll INF=(1LL<<60);
const int INF2=(1<<30);
//using mint=modint1000000007;
//using mint=modint998244353;

int main() {
    ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    //l*c~r*cの中で1000の倍数に近いもの
    ll l,r,c;cin>>l>>r>>c;
    ll ans=1000;
    for(ll i=l;i<min(l+1000,r+1);i++){
        ll res=(1000-i*c%1000)%1000;
        ans=min(ans,res);
    }
    cout<<ans<<endl;
    return 0;
}