#include<iostream>
using namespace std;
int main(){
  int a,x,y,b=0;
  int c[1000]={};
  cin>>x>>y;
  for(int i=x;i<y;i++){
  	if(i%4==0&&i%100!=0||i%400==0){
  		c[b]=i;
		b++;
	  }
	  
  }
  cout<<b<<endl;
	for(int i=0;i<=b;i++){
  	if(c[i]!=0){
  	cout<<c[i]<<" ";
	}
  }
 return 0;
}
 ``` cpp