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