import math
def sieve_of_eratosthenes(n):
    prime = [True for i in range(n+1)]
    prime[0] = False
    prime[1] = False

    sqrt_n = math.ceil(math.sqrt(n))
    for i in range(2, sqrt_n):
        if prime[i]:
            for j in range(2*i, n+1, i):
                prime[j] = False

    return prime

n = int(input())
prm = sieve_of_eratosthenes(n)
pri = []
pset = set()
for i in range(n+1):
    if prm[i] == True:
        pri.append(i)
        pset.add(i)

ans = 0

for i in range(len(pri)):
    r2 = pri[len(pri)-1-i]**2
    if r2 > 10**6:
        continue
    for j in range(len(pri)):
        if r2-pri[j] in pset:
            ans += 1

print(ans)