题解

#include<iostream>
using namespace std;
int main(){
    int x,y,sum=0;
    cin>>x>>y;
    for(int i=x;i<=y;i++){
        if(i%4==0){
            if(i%400==0){
                sum++;
            }else if(i%100==0){
                continue;
            }else{
                sum++;
            }
        }else{
            continue;
        }
    }
    cout<<sum<<"\n";
    for(int i=x;i<=y;i++){
        if(i%4==0){
            if(i%400==0){
                cout<<i<<' ';
            }else if(i%100==0){
                continue;
            }else{
                cout<<i<<' ';
            }
        }else{
            continue;
        }
    }
    return 0;
}