#include<bits/stdc++.h>
using namespace std;
typedef long double ld;
typedef long long ll;
//#define int ll
#define endl '\n'
#define fi first
#define se second
#define pii pair<int, int>
#define rep(i,a,n,k) for(int i=a;i<=n;i+=k)
#define per(i,a,n,k) for(int i=a;i>=n;i-=k)
/*·········································*/
const int N = 1e6 + 10;
int l, r;
ll res[N], ans;

void solve()
{
	memset(res, 0x3f, sizeof res);
	cin >> l >> r;
	rep(i,1,r,1)
	{
		ll x = 0;
		rep(j,i,r,i) if(j >= l && j <= r)
		{
			if(!x) x = j;
			else res[j] = min(res[j], x * j / i);
		}
	}
	rep(i,l+1,r,1) ans += res[i];
	cout << ans;
}

signed main()
{
	ios::sync_with_stdio(0);
	cin.tie(0),cout.tie(0);
	int t = 1;
	//cin>>t;
	while(t--) solve();
	return 0;
}