#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define REP(i,a,n) for(int i=(a); i<(int)(n); i++) #define rep(i,n) REP(i,0,n) #define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it) #define ALLOF(c) (c).begin(), (c).end() typedef long long ll; #define MAX_PRIME 10000000 bool isprime[MAX_PRIME+1]; vector primes; void init_prime(){ fill(isprime, isprime+MAX_PRIME+1, true); isprime[0] = isprime[1] = false; for(int i = 2; i <= MAX_PRIME; i++) { if (isprime[i]) { primes.push_back(i); for(int j = i*2; j <= MAX_PRIME; j += i) isprime[j] = false; } } } int main(){ ios::sync_with_stdio(false); init_prime(); int N, L; cin >> N >> L; ll ret = 0; rep(i,primes.size()){ ll p = primes[i]; if(p * (N-1) > L) continue; ll dif = L - p * (N-1); ret += dif + 1; } cout << ret << endl; return 0; }