n = int(input())
primes = []
ans = 0
r = set()
pq = set()
count = [0]*(n+1)
for i in range(2,n+1):
    if count[i]:
        continue
    primes.append(i)
    for j in range(i,n+1,i):
        count[j] += 1

    r.add(i**2)
    pq.add(i)

    # for j in r:
    #     if j-i in pq:
    #         if i == j-i:
    #             ans += 1
    #         else:
    #             ans += 2

for i in r:
    if i > 2*n:
        continue
    for p in primes:
        if p > i:
            break
        if i-p < p:
            break
        if i-p in pq:
            if p == i-p:
                ans += 1
            else:
                ans += 2
print(ans)