#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};
int main() {
  int n;
  cin >> n;
  cout << a[n - 1];
}
