def sieve(n):
    is_prime = [True for _ in range(n+1)]
    is_prime[0] = False

    for i in range(2, n+1):
        if is_prime[i-1]:
            j = 2 * i
            while j <= n:
                is_prime[j-1] = False
                j += i
    table = [ i for i in range(1, n+1) if is_prime[i-1]]
    return is_prime, table

N = int(input())
_,t = sieve(2*N)
s=set(t)
ppow = []
lent = len(t)
i = 0
while  i<lent and t[i]**2<=2*N:
    ppow.append(t[i]**2)
    i+=1
ans = 0

for p in ppow:
    for j in range(lent):
        if p - t[j] in s and p - t[j]<=N and t[j]<=N:
            ans+=1
        if t[j]>=p:
            break
print(ans)