#include <bits/stdc++.h>
using namespace std;
int main() {
    vector<long long> qqs;
    vector<int> nums = {1,2,3,4,5,9};
    for (int A : nums) {
        for (int B : nums) {
            for (int C : nums) {
                for (int D : nums) {
                    for (int E : nums) {
                        for (int F : nums) {
                            long long num = 0;
                            num = num * 10 + A; 
                            num = num * 10 + B;   
                            num = num * 10 + C;   
                            num = num * 10 + B;  
                            num = num * 10 + D;   
                            num = num * 10 + A;   
                            num = num * 10 + D;   
                            num = num * 10 + E; 
                            num = num * 10 + F;
                            qqs.push_back(num);
                        }
                    }
                }
            }
        }
    }
    sort(qqs.begin(), qqs.end());
    int n;
    cin >> n;
    if (n < 1 || n > qqs.size()) {
        cout << "You cheater!" << endl;
    } else {
        cout << qqs[n-1] << endl;
    }
    
    return 0;
}