#include <bits/stdc++.h>
using namespace std;
int arrAns[30] = {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},
    nPos;
int main() {
  scanf("%d", &nPos);
  printf("%d", arrAns[nPos - 1]);
  return 0;
}
