from math import sqrt

def primes(n):
    is_prime = [True] * (n + 1)
    is_prime[0] = False
    is_prime[1] = False
    for i in range(2, int(n**0.5) + 1):
        if not is_prime[i]:
            continue
        for j in range(i * 2, n + 1, i):
            is_prime[j] = False
    l = [False]*(n+1)
    for i in range(n+1):
        if is_prime[i]:
            l[i] = True

    return l

N = int(input())
R = int(sqrt(10**6))
arr = primes(5*(10**5)+1)
count = 0
for r in range(1,min(N,R)+1):
    if arr[r]:
        for p in range(1,N+1):
            q = r**2-p
            if q > N or q < 1:
                continue
            if arr[p] and arr[q]:
                count += 1

print(count)