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

vector<long long> t;
void bt(int pos, string s) {
    if (pos == 15) {
        while (s.size() > 1 && s[0] == '0') {
            s = s.substr(1, s.size()-2);
        }
        long long num = 0;
        for (auto c : s) {
            num = num * 2 + c - '0';
        }
        t.push_back(num);
        return;
    }
    bt(pos+1, "1" + s + "1");
    bt(pos+1, "0" + s + "0");
}

int main() {
    bt(0, "0");
    bt(0, "1");
    bt(0, "");
    sort(t.begin(), t.end());
    t.erase(unique(t.begin(), t.end()), t.end());
    int m;
    cin>>m;
    cout << t[m] << '\n';
    return 0;
}