#include <iostream>
using namespace std;

int isbal (long long i)
{
	int cnt[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
	while (i)
	{
		++cnt[i % 10];
		i /= 10;
	}
	for (int i = 0; i < 10; i += 2) if (cnt[i] != 0 && (cnt[i] & 1) == 0) return 0;
	for (int i = 1; i < 10; i += 2) if (cnt[i] != 0 && (cnt[i] & 1) != 0) return 0;
	return 1;
}

int main ()
{
	long long a, b;
	cin >> a >> b;
	long long res = 0;
	for (int i = a; i <= b; ++i) res += isbal (i);
	cout << res << endl;
	return 0;
}
