#include <bits/stdc++.h>
using namespace std;
int main() {
  int a;
  int num[] = {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};
  cin >> a;
  if (a >= 1 && a <= 30) {
    cout << num[a - 1] << endl;
  }
  return 0;
}
