#include<bits/stdc++.h>
using namespace std;
int main (){
	int x,y,a[1010],k=0;
	cin>>x>>y;
	for(int i=x;i<=y;i++){
		if((i%400==0||i%4==0)&&i%100!=0){
			k++;
			a[k]=i;
		}
	} 
	cout<<k<<"\n";
	for(int i=1;i<=k;i++){
		cout<<a[i]<<" ";
	} 
	return 0;
}