#include <algorithm>
#include <functional>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <bitset>
#include <climits>

#define all(c) (c).begin(), (c).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define pb(e) push_back(e)
#define mp(a, b) make_pair(a, b)
#define fr first
#define sc second

const int INF=100000000;
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
using namespace std;
typedef pair<int ,int > P;
typedef long long ll;

const int MAX_N = 1000000009;
vector<int> ans;

bool ok(int a) {
    while(a) {
        if(a%10 == 4 || a%10 == 6) return false;
        a /= 10;
    }
    return true;
}
void init() {
    ans.reserve(MAX_N);
    rep(i,MAX_N) {
        if(!i) continue;
        if(ok(i)) ans.pb(i);
    }

}
int main() {
    init();
    int n;
    while(cin>>n) {
        if(!n) break;
        cout<<ans[n-1]<<endl;

    }
    return 0;
}