#include <bits/stdc++.h>
using namespace std;
bool not_prim(int num) {
  for (int i = 2; i <= num / 2; i++) {
    if (num % i == 0) return true;
  }
  return false;
}
struct q {
  int id;
  int j;
};
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n = 1;
  int arr[] = {4,   22,  27,  58,  85,  94,   121,  166, 202, 265, 274,
               319, 346, 355, 378, 382, 391,  438,  454, 483, 517, 526,
               535, 562, 576, 588, 627, 634,  636,  645, 648, 654, 663,
               666, 690, 706, 728, 729, 762,  778,  825, 852, 861, 895,
               913, 915, 922, 958, 985, 1086, 1111, 1165};
  long long a, s = 0, d = 4, f, q, e, r, w;
  cin >> a;
  a--;
  cout << arr[a];
  cin >> n;
  return 0;
}
