import sys def input(): return sys.stdin.readline().strip() def list2d(a, b, c): return [[c] * b for i in range(a)] def list3d(a, b, c, d): return [[[d] * c for j in range(b)] for i in range(a)] def list4d(a, b, c, d, e): return [[[[e] * d for j in range(c)] for j in range(b)] for i in range(a)] def ceil(x, y=1): return int(-(-x // y)) def INT(): return int(input()) def MAP(): return map(int, input().split()) def LIST(N=None): return list(MAP()) if N is None else [INT() for i in range(N)] def Yes(): print('Yes') def No(): print('No') def YES(): print('YES') def NO(): print('NO') sys.setrecursionlimit(10 ** 9) INF = 10 ** 18 MOD = 10 ** 9 + 7 EPS = 10 ** -10 def eratosthenes_sieve(n): """ 素数列挙(エラトステネスの篩) """ table = [0] * (n + 1) prime_list = [] for i in range(2, n + 1): if table[i] == 0: prime_list.append(i) for j in range(i + i, n + 1, i): table[j] = 1 return prime_list N = INT() primes = eratosthenes_sieve(N) S = set(primes) R = [] for p in primes: if p**2 > N: break R.append(p**2) ans = 0 for p in primes: for r2 in R: q = r2 - p if q in S: ans += 1 print(ans)