Oktalni Solution:

#include <bits/stdc++.h>
using namespace std;

map<string, int> mapping = {
    {"000", 0},
    {"001", 1},
    {"010", 2},
    {"011", 3},
    {"100", 4},
    {"101", 5},
    {"110", 6},
    {"111", 7}
};

int main(){
    // #ifndef TESTING
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);
    // #endif

    queue<char> q;
    char c;
    while(cin >> c){
        q.push(c);
    }
    string s, result;
    map<string, int>::iterator findr;
    int toRemove = q.size() % 3;
    if(toRemove){
        int padding = 3 - toRemove;
        while(padding--){
            s.push_back('0');
        }
        while(toRemove--){
            s.push_back(q.front());
            q.pop();
        }
        findr = mapping.find(s);
        cout << findr->second;
    }
    while(q.size()){
        s.clear();
        s.push_back(q.front());
        q.pop();
        s.push_back(q.front());
        q.pop();
        s.push_back(q.front());
        q.pop();
        findr = mapping.find(s);
        cout << findr->second;
    }
    
    return 0;   
}