#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define pb push_back
#define fi first
#define se second
#define nn '\n'
#define pi pair<ll,ll>
#define unmp unordered_map
#define uns unordered_set
ll mod = 1e9+7;
const int N = 1e5 + 5;
int MOD = 998244353;
int bit[200000];
int l, r;
int s[N];

void sieve(){
	for(int i=1;i<=N;i++){
		for(int j=i;j<=N;j+=i){
			s[j] += i;
		}
	}
}
int main() {
	//freopen("ATRISET.INP", "r", stdin);
	//freopen("ATRISET.OUT", "w", stdout);
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	sieve();
	cin >> l >> r;
	int dem = 0;
	for(int i = l ; i <= r; i++){
        if(s[i] - i > i){
            dem++;
        }
	}
	cout << dem << nn;
	return 0;
}