#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, 706, 728,  729,  762,
           778, 825, 852, 861, 895, 913, 915, 922, 958, 985, 1086, 1111, 1165};
void solve(int n) {
  int i, j, k, m, l, q, w;
  printf("%d", a[n - 1]);
}
int main() {
#pragma warning(disable : 4996);
  int n;
  while (scanf("%d", &n) != EOF) {
    solve(n);
    return 0;
    printf("\n");
  }
  return 0;
}
