#include <bits/stdc++.h>
#include <atcoder/all>

using namespace std;
using namespace atcoder;
typedef long long ll;
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
static const double pi = 3.141592653589793;
const ll INF = 1LL << 60;
const ll mod = 1000000007;
const ll imod = 998244353;
using mint = modint998244353;
vector<int> dx = {1, 0, -1, 0}, dy = {0, 1, 0, -1};
ll P(ll x, ll n) {
  ll ret = 1;
    while (n > 0) {
      if (n & 1) ret *= x;
      x *= x;
      n >>= 1;
  }
  return ret;
}

void seek(bool f){
  cout << (f ? "Yes" : "No") << endl;
}

int main(){
	ll C = 101;
	vector<bool> prime(C, true);
	prime[0] = prime[1] = false;
	for(int i = 2; i < C; i++){
		if(prime[i]){
			for(int j = 2; i * j < C; j++){
				prime[i * j] = false;
			}
		}
	}
	int ans = 0;
	int A, B;
	cin >> A >> B;
	for(int i = A; i <= B; i++){
		if(prime[i]){
			ans += P(i, 3) - P(i, 2) + P(i, 1) + 1;
		}
	}
	cout << ans << endl;
}