#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=1e5+10;
int n,m;
signed main(){
    int l,r,c; cin>>l>>r>>c;
    int ans=1000;
    for(int i=l;i<=min(r,l+1000);i++){
        int now=1000-c*i%1000;
        ans=min(ans,now);
    }
    cout<<ans;
    return 0;
}