#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <cstring>
#include <queue>
#include <stack>
#include <math.h>
#include <iterator>
#include <vector>
#include <string>
#include <set>
#include <math.h>
#include <iostream> 
#include<map>
#include <stdlib.h>
#include <list>
#include <typeinfo>
#include <list>
#include <set>
#include <iomanip>
using namespace std;
#define MAX_MOD 1000000007
#define REP(i,n) for(int i = 0;i < n;++i)
long long m[100000000] = {};
int main() {
	int n, l;
	cin >> n >> l;
	m[1] = true;
	for (int i = 2;i < sqrt(l) + 1;++i) {
		if (m[i] == false) {
			for (int q = 2;i*q < l + 1;++q) {
				m[i*q] = true;
			}
		}
	}
	n--;
	long long ans = 0;
	for (long long i = 2;i >= 0;++i) {
		if (m[i] == false) {
			long long hoge = n*i;
			if (l - hoge >= 0) {
				ans += l - hoge + 1;
			}
			else {
				cout << ans << endl;
				return 0;
			}
		}
	}
}