import java.util.*;

public class Main {
    
    static int[] dy = {0,1,0,1};
    static int[] dx = {1,0,1,0};
    
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        
        int l = sc.nextInt();
        int r = sc.nextInt();
        int c = sc.nextInt();

        int ans = 999;
        for(int i = l ; i <= r ; i++){
            
            int x = ((i % 1000) * (c % 1000)) % 1000;
            
            if(x == 0){
                ans = 0;
                break;
            }
            
            ans = Math.min(ans , 1000 - x);
            
        }
        
        System.out.println(ans);
        
    }
    
}