n = int(input())

# x = (p*a+b)/(p**2-1) > 1/n
# (p*a+b)*n > p**2-1
# 0 > p**2 - p*a*n -1 - b*n
# 0 > (p-a*n/2)**2 -1 - b*n - (a*n/2)**2
M = 10**9+1
def f(p,a,b):
    return p**2-p*a*n-1-b*n < 0
ans = 0


for a in range(10):
    for b in range(10):
        if a == b:
            continue

        if n >= 10**4:
            for p in range(max(a,b)+1,100):
                if f(p,a,b):
                    ans += 1

            ll = 100
            l = ll
            r = M
            while l+1 < r:
                m = (r+l)//2
                if f(m,a,b):
                    l = m
                else:
                    r = m
            ans += l-ll+1
        else:
            for p in range(max(a,b)+1,2*10**5):
                if f(p,a,b):
                    ans += 1

print(ans)