#include<iostream>
using namespace std;
int main()
{
	int x, y, num = 0;
	cin >> x >> y;
	for (int i = x; i <= y; i++)
	{
		if (i % 4 == 0 && i % 100 != 0 || i % 400 == 0)
		{
			num++;
		}
	}
	cout << num << endl;
	for (int i = x; i <= y; i++)
	{
		if (i % 4 == 0 && i % 400 != 0 || i % 400 == 0)
		{
			cout << i<<" ";
		}
	}
	return 0;  
}