#include <iostream>
#include <cmath>
using namespace std;
int main()
{
	int a, b, s, d,e, f, i, h, k;
	cin >> a >> b;
	k = a;
	i = 0;
	s = 0;
	d = 0;
	f = 0;
	for (k = a; k <= b; k++)
	{
		do
		{
			h = k / 10;
			i++;
		} while (h != 0);
		for (d = 1; d <= i; d++)
		{
			f = k / 10;
			s = s + pow(f, i);
		}
		if (s == k)
		{
			e = 1;
			cout << k;
		}

	}
	if (e != 1)
		cout << "-1";

	cin.get();
	cin.get();
	return(0);


}