#include <bits/stdc++.h>
using namespace std;
int a[100] = {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};
int main() {
  int b;
  cin >> b;
  cout << a[b - 1] << endl;
}
