#include <bits/stdc++.h>
using namespace std;
int a[52] = {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 n;
  scanf("%d", &n);
  printf("%d", a[n - 1]);
  return 0;
}
