#include<bits/stdc++.h>
#define PRINT(x) cerr<<#x<<'='<<x<<endl;
#define NL(x) " \n"[(x)]
#define lld long long
#define pil pair<int,lld>
#define pli pair<lld,int>
#define pll pair<lld,lld>
#define pii pair<int,int>
#define pb push_back
#define fi first
#define se second
#define mid (l+r)/2
#define endl '\n'
#define all(a) begin(a),end(a)
#define sz(a) int((a).size())
#define LINF 1000000000000000LL
#define INF 1000000000
#define EPS 1e-9
using namespace std;
lld d[10000010];
int main() {
ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);cerr.tie(0);
int A, B; cin >> A >> B;
lld rez = 0;
for(int i = 1; i <= B; i++) {
for(int j = 2*i; j <= B; j+=i) d[j] -= i;
if(i >= A) rez += abs(i+d[i]);
}
cout << rez;
return 0;
}
