#include<iostream>
using namespace std;
int x,y,ans,sum,a[1001];
int main()
{
	cin>>x>>y;
	for(int i=1;i<=y-x;i++)
	{
		sum=x+1;
		if(sum%4==0)
		{
			if(sum%100==0)
			{
				if(sum%400==0)
				{
					a[i]=sum;
					ans++;
				}
				else
				{
					continue;
				}
			}
			else
			{
				continue;
			}
			a[i]=sum;
			ans++;
		}
	}
	cout<<ans<<endl;
	cout<<a[1];
	for(int i=2;i<=y-x;i++)
	{
		cout<<" ";
		cout<<a[i];
	}
	return 0;
}