#include <iostream>
using namespace std;

int main()
{
    int L,R,C,A;
    A = 1000;
    cin >> L >> R >> C;
    for (int i = L; i < R+1; i++){
        if (A > (i * C / 1000 + 1) * 1000 - i * C) {
            A = (i * C / 1000 + 1) * 1000 - i*C;
        }
    }
    cout << A << endl;
    return 0;
}