n = int(input())

def func(x, a, b):
    return x**2 - n * a * x - n * b - 1

ans = 0
for a in range(10):
    for b in range(10):
        if a == b:
            continue
        min_p = max(a, b) + 1
        if func(min_p, a, b) >= 0:
            continue
        left, right = min_p, 10**9 + 1
        while right - left > 1:
            mid = (left + right) // 2
            if func(mid, a, b) < 0:
                left = mid
            else:
                right = mid
        ans += left - min_p + 1
print(ans)