#include <bits/stdc++.h>
using namespace std;
int p(string S,int i,int count){
    if(S.size()==i)return 0;
    if(S.at(i)=='0'){count/=4;return p(S,i+1,count);}
    if(S.at(i)=='3'){count/=4;return p(S,i+1,count)+count;}
    if(S.at(i)=='6'){count/=4;return p(S,i+1,count)+count*2;}
    if(S.at(i)=='9'){count/=4;return p(S,i+1,count)+count*3;}
    if(S.at(i)<'3')return count/4;
    if(S.at(i)<'6')return count/4*2;
    if(S.at(i)<'9')return count/4*3;
}
int main(){
    int N;cin>>N;
    if(N<100){
        cout<<(N-9)/3<<endl;
        return 0;
    }
    int ans=30;
    string S=to_string(N);
    int count=48;
    for(int i=3;i<S.size();i++){
        ans+=count;
        count*=4;
    }
    cout<<p(S,0,count)+ans<<endl;
}