#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using vin=vector<int>;
using vll=vector<long long>;
using vvin=vector<vector<int>>;
using vvll=vector<vector<long long>>;
using vstr=vector<string>;
using vvstr=vector<vector<string>>;
using vch=vector<char>;
using vvch=vector<vector<char>>;
using vbo=vector<bool>;
using vvbo=vector<vector<bool>>;
using vpii=vector<pair<int,int>>;
using pqsin=priority_queue<int,vector<int>,greater<int>>;
#define mp make_pair
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep2(i,s,n) for(int i=(s);i<(int)(n);i++)
#define all(v) v.begin(),v.end()
#define decp(n) cout<<fixed<<setprecision((int)n)
const ll inf=1e9+7;
const ll INF=1e18;
const ll mod=998244353;

int main(){
    int n;cin>>n;
    string s=to_string(n);
    int k=s.size();
    vvll dp(k+1,vll(2));
    dp[0][0]=(ll)1;
    int tmp;
    rep(i,k){
        tmp=s[i]-'0';
        dp[i+1][1]=4*dp[i][1];
        rep(j,tmp)if(j%3==0)dp[i+1][1]+=dp[i][0];
        if(tmp%3==0)dp[i+1][0]=dp[i][0];
    }
    ll ans=dp[k][0]+dp[k][1]-(ll)4;//0,3,6,9
    rep2(i,10,min(n+1,100))if((i/10+i%10)%3==0&&((i/10)%3!=0||(i%10)%3!=0))ans++;
    cout<<ans<<endl;
}