#include<iostream>
using namespace std;
int main()
{
    int n1,n2,i,ans=0;
    cin>>n1>>n2;
    for(i=n1;i<=n2;i++)
    if(i%4==0||i%2!=0)ans++;  //奇数或4的倍数
    cout<<ans<<endl;
    return 0;
}