N,L = map(int,input().split()) def getPrimes(): isPrime = [True for i in range(4999999 + 1)] isPrime[0] = isPrime[1] = False primes = [] for i in range(2,4999999 + 1): if not isPrime[i]: continue if L < i * (N - 1): break for j in range(i * 2,4999999 + 1,i): isPrime[j] = False primes.append(i) return primes primes = getPrimes() ans = 0 for p in primes: if L < p * (N - 1): break ans += (L - p * (N - 1)) + 1 print(ans)