#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <atcoder/modint>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(int i=0; i<(int)(n); i++)
const i64 INF = 1001001001001001001;

using Modint = atcoder::static_modint<998244353>;


int main(){
    long long L, R, C; cin >> L >> R >> C;
    if(R/1000 > L/1000 + 1){ cout << "0\n"; return 0; }
    i64 ans = 999;
    for(long long x=L; x<=R; x++) ans = min(ans, (1000 - C*x % 1000) % 1000);
    cout << ans << endl;
    return 0;
}



struct ios_do_not_sync{
    ios_do_not_sync(){
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
    }
} ios_do_not_sync_instance;