package Opseg;

import java.util.Scanner;

import org.omg.Messaging.SyncScopeHelper;

public class Opseg {

    public static int suma(int k)
    {
        int sum=0;
        while(k != 0)
        {
            sum+=k%10;
            k/=10;
        }
        return sum;
    }

    public static int solve(int a, int b, int N)
    {
        Array<Integer> niza = new Array<Integer>(b-a);
        int broj=0;
        for(int i=a; i<=b; i++)
        {
            int s = suma(niza.get(i));
            int izraz = (niza.get(i)*niza.get(i))+s+(200*niza.get(i));

            if(N == izraz)
            {
                broj=niza.get(i);
            }
        }
        return broj;
    }

    public static void main(String[] args) {

        Scanner s = new Scanner(System.in);

        int N = s.nextInt();
        int a = s.nextInt();
        int b = s.nextInt();

        int n = b-a;

        //Array<Integer> niza = new Array<Integer>(n);

        System.out.println(solve(a, b, N));
        //System.out.println(suma());
    }
}