S = input()
N = len(S)

dp = [[0]*2 for _ in range(N+1)]
dp[0][0] = 1
for i, s in enumerate(S):
    nd = int(s)
    for j in range(2):
        for d in range(0, 10, 3):
            ni = i + 1
            nj = j
            if nj == 0:
                if d > nd:
                    continue
                if d < nd:
                    nj = 1
            dp[ni][nj] += dp[i][j]

ans = dp[N][0] + dp[N][1] - 4
for i in range(10, min(int(S)+1, 100)):
    if i % 3 == 0 and (i % 10) % 3 != 0:
        ans += 1

print(ans)