import sys

if len(sys.argv) == 2:
    sys.stdin = open(sys.argv[1])

n = int(input())

if n < 10:
    print(0)
elif n < 100:
    print(n // 3 - 3)
else:
    ans = 30 - 12
    s = str(n)
    d = len(s)
    C = [0 for _ in range(10)]
    C[0] = 1
    for i in range(1, 10):
        C[i] = C[i - 1] * 4
    ok = True
    for i in range(d):
        num = int(s[i])
        for c in range(0, num, 3):
            ans += C[d - i - 1]
        if num % 3 != 0:
            ok = False
            break
    if ok:
        ans += 1
    print(ans - 4)