n = int(input())
X1 = [1, 4, 7]
X2 = [2, 5, 8]
X0 = [0, 3, 6, 9]
X = set()
for a in X1:
    for b in X2:
        X.add(10*a+b)
        X.add(10*b+a)
import itertools
X0 = [str(c) for c in X0]
for p in itertools.product(X0, repeat=10):
    x = ''.join(p)
    x = int(x)
    if 0 <= x <= 9:
        continue
    X.add(x)
X = list(X)
X.sort()
import bisect
ans = bisect.bisect_right(X, n)
print(ans)