int runnian(int a,int *k)
{
    int b;
    b=a%400;
    if(b==0){
        *k=*k+1;
    }
    else{
        b=a%4;
        if(b==0){
            *k=*k+1;
        }
    }
	return a;
}
int main(){
    int x,y;
    scanf("%d %d",&x,&y);
    int num;
    int k=0;
    for(int i=x;i<=y;i++){
       runnian(i,&k);
    }
    int b[k];
    int t=0;
    int qwe=0;
    for(int i=x;i<=y;i++){
        t=0;
        runnian(i,&t);
        if(t==1){
            b[qwe]=i;
            qwe=qwe+1;
        }
    }
    printf("%d\n",qwe);
    for(int i=0;i<=k-1;i++){
        printf("%d ",b[i]);
    }
    return 0;
}