#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> P;
typedef pair<int,int> Pi;
#define rep(i,n) for(ll i=0;i<n;i++)
#define FOR(i,a,b) for(ll i=a;i<b;i++)
#define fi first
#define se second
#define endl "\n"

template<typename T> inline bool chmax(T &a, T b){if(a<b){a=b;return true;}return false;}
template<typename T> inline bool chmin(T &a, T b){if(a>b){a=b;return true;}return false;}
template<typename T> ostream& operator<<(ostream& s,const complex<T>& d) {return s<<"("<<d.real()<<", "<<d.imag()<< ")";}
template<typename T1, typename T2> ostream& operator<<(ostream& s,const pair<T1,T2>& d) {return s<<"("<<d.first<<", "<<d.second<<")";}
template<typename T> ostream& operator<<(ostream& s, const vector<T>& d){int len=d.size();rep(i,len){s<<d[i];if(i<len-1) s<<" ";}return s;}
template<typename T> ostream& operator<<(ostream& s,const vector<vector<T>>& d){int len=d.size();rep(i,len){s<<d[i]<<endl;}return s;}
template<typename T> ostream& operator<<(ostream& s,const set<T>& v){s<<"{ ";for(auto itr=v.begin();itr!=v.end();++itr) {if (itr!=v.begin()) {s<< ", ";}s<<(*itr);}s<<" }";return s;}
template<typename T> ostream& operator<<(ostream& s,const multiset<T>& v){s<<"{ ";for(auto itr=v.begin();itr!=v.end();++itr) {if (itr!=v.begin()) {s<< ", ";}s<<(*itr);}s<<" }";return s;}
template<typename T1, typename T2> ostream& operator<<(ostream& s,const map<T1,T2>& m){s<<"{"<<endl;for(auto itr=m.begin();itr!=m.end();++itr){s<<" "<<(*itr).first<<" : "<<(*itr).second<<endl;}s<<"}"<<endl;return s;}

const ll mod=1'000'000'007;
const ll inf=1'000'000'000'000'000'00;
const int INF=1'000'000'000;
const double EPS=1e-10;
const double PI=acos(-1);

int main(){
	cin.tie(0);ios::sync_with_stdio(false);
	int n;
	cin>>n;
	int D=to_string(n).size();
	int ans=0;
	if(D==2){
		for(int x=12;x<=n;x+=3){
			string s=to_string(x);
			int d=s.size();
			reverse(begin(s),end(s));
			bool flag=true;
			rep(i,d)rep(j,d){
				if(i>=j) continue;
				int now=int(s[i]-'0')+int(s[j]-'0');
				if(now%3) flag=false;
			}
			if(flag){
				ans++;
			}
		}
	}else{
		ans=30;
		rep(S,1<<10)rep(T,1<<10){
			string now;
			rep(i,10){
				if(S & 1<<i){
					if(T & 1<<i) now+='0';
					else now+='3';
				}else{
					if(T & 1<<i) now+='6';
					else now+='9';
				}
			}
			ll x=stoll(now);
			if(100<=x && x<=n) ans++;
		}
	}
	cout<<ans<<endl;
}