#include <bits/stdc++.h>
int main() {
  int Ans[31] = {0,   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};
  int x;
  scanf("%d", &x);
  printf("%d", Ans[x]);
  return 0;
}
