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

vector<string> radixArr = {"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"};
// 进制转换
string radixConvert(int x,int d){
    string str = "";
    while(x!=0){
        if(x%d >= 16){
            return "null";
        }
        str.insert(0,radixArr[x%d]);
        x /= d;
    }
    return str;
}


int main(){
    int n;
	while(cin >> n){
		cout << radixConvert(n,8) << endl;
	}
    return 0;
}