#include<iostream>
using namespace std;
long long n,s=0,n1,i;
int main()
{
    cin>>n>>n1;
    i=n;
    while(i<=n1)
    {
        while(i<=n1)
        {
            if(i+40000000000000<=n1)
            i+=40000000000000,s+=9700000000000;
            else
                if(i+40000000000<=n1)
                i+=40000000000,s+=9700000000;
                else
                    if(i+4000000<=n1)
                    i+=4000000,s+=970000;
                    else
                    for(i;i<=n1;i++)
                    if(i%400==0||i%4==0&&i%100!=0) s++;
        }
    }
    cout<<s;
    return 0;
}
//可以化简一下

using namespace std;
int main()
{
long long a,b,year;long long cnt=0;cin>>a>>b;
for(year=a;year<=b;year++)
{
if(year%400==0||((year%100)!=0&&(year%4==0)))
cnt++;
}
cout<<cnt<<endl;
return 0;
}