#include #define rep(i,a,b) for(int i=a;i=b;i--) #define fore(i,a) for(auto &i:a) #define all(x) (x).begin(),(x).end() //#pragma GCC optimize ("-O3") using namespace std; void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); } typedef long long ll; const int inf = INT_MAX / 2; const ll infl = 1LL << 60; templatebool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; } templatebool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; } //--------------------------------------------------------------------------------------------------- /*---------------------------------------------------------------------------------------------------             ∧_∧       ∧_∧  (´<_` )  Welcome to My Coding Space!      ( ´_ゝ`) /  ⌒i @hamayanhamayan0     /   \    | |     /   / ̄ ̄ ̄ ̄/  |   __(__ニつ/  _/ .| .|____      \/____/ (u ⊃ ---------------------------------------------------------------------------------------------------*/ int N; string S; //--------------------------------------------------------------------------------------------------- int cmb[10]; int only0369() { int len = S.length(); cmb[0] = 1; rep(i, 1, 10) cmb[i] = cmb[i - 1] * 4; int ans = 0; bool ok = true; rep(i, 0, len) { int num = S[i] - '0'; rep(c, 0, num) if (c % 3 == 0) ans += cmb[len - i - 1]; if (num % 3 != 0) { ok = false; break; } } if (ok) ans++; return ans - 4; } //--------------------------------------------------------------------------------------------------- int special() { int ans = 0; rep(x, 10, 100) if (x <= N) { int tot = (x % 10) + (x / 10); if ((x % 10) % 3 == 0 && (x / 10) % 3 == 0) continue; if (x % 3 == 0 && tot % 3 == 0) ans++; } return ans; } //--------------------------------------------------------------------------------------------------- void _main() { cin >> N; S = to_string(N); cout << only0369() + special() << endl; }