s = input()

n = int(s)
num = len(s)

ans = 0

for i in range(4 ** num):
    now = i
    cnt = 0
    for j in range(num):
        cnt *= 10
        cnt += (now % 4) * 3
        now //= 4
    if (cnt <= n):
        ans += 1

for i in range(10, min(100, n + 1)):
    a = i % 10
    b = i // 10
    if ((a % 3 == 1 and b % 3 == 2) or (a % 3 == 2 and b % 3 == 1)):
        ans += 1

print(ans - 4)