include <bits/stdc++.h>

using namespace std; int main(){ int a,b; int c[500]; int d=0; cin>>a>>b; for(int i=a;i<=b;i++){ if(((i%4==0)&&(i%100!=0))||(i%400==0)){ c[d]=i; d+=1; } } cout << d << endl; for (int i=0;i<=d;i++){ cout << c[i]<<" "; } }