#include<iostream>
using namespace std;
int part(int m, int n, int brr[]);
int main() {
	int x, y,i, n, arr[100] = { 0 };
	cin >> x >>y;
	n = part(x, y,arr);
	cout << n;
    cout<<endl;
	for (i = 0; i <n; i++) {
		cout <<arr[i]<<" " ;
	}
}
int part(int m, int n,int brr[]) {
	int ch = n - m, i,count=0;
	for (i = 0; i < n-m+1; i++) {
		if ((m+i) % 4 == 0 && (m+i) % 100 != 0) {
			brr[count] = m+i;
			count++;
		}
		else if ((i+m) % 400 == 0) {
			brr[count] = m + i;
			count++;
		}
	}
	return count;
}