#include <bits/stdc++.h>

#ifndef LOCAL_
#define fprintf if( false ) fprintf
#endif // LOCAL_
#define dumpi(x1) fprintf(stderr, "#%s.%d (%s) = (%d)\n", __func__, __LINE__, #x1, x1);
#define dumpii(x1, x2) fprintf(stderr, "#%s.%d (%s, %s) = (%d, %d)\n", __func__, __LINE__, #x1, #x2, x1, x2);
#define dumpiii(x1, x2, x3) fprintf(stderr, "#%s.%d (%s, %s, %s) = (%d, %d, %d)\n", __func__, __LINE__, #x1, #x2, #x3, x1, x2, x3);
#define dumpl(x1) fprintf(stderr, "#%s.%d (%s) = (%ld)\n", __func__, __LINE__, #x1, x1);
#define dumpll(x1, x2) fprintf(stderr, "#%s.%d (%s, %s) = (%ld, %ld)\n", __func__, __LINE__, #x1, #x2, x1, x2);
#define dumpd(x1) fprintf(stderr, "#%s.%d (%s) = (%lf)\n", __func__, __LINE__, #x1, x1);
#define dumpdd(x1, x2) fprintf(stderr, "#%s.%d (%s, %s) = (%lf, %lf)\n", __func__, __LINE__, #x1, #x2, x1, x2);

long dp[32][3][2];

int main() {
  dp[1][0][0] = 3;
  dp[1][0][1] = 1;
  dp[1][1][0] = 3;
  dp[1][1][1] = 0;
  dp[1][2][0] = 3;
  dp[1][2][1] = 0;

  int x;
  scanf("%d", &x);
  for(int i = 2; i <= x; ++i) {
    for(int j = 1; j < i; ++j) {
      for(int k = 1; k <= 9; ++k) {
        for(int m = 0; m < 3; ++m) {
          for(int c : {0, 1}) {
            dp[i][(m+k)%3][c||(k==3)] += dp[j][m][c];
          }
        }
      }
    }
  }
  // for(int i = 1; i <= x; ++i) {
  //   for(int m = 0; m < 3; ++m) {
  //     for(int c = 0; c <= 1; ++c) {
  //       dumpiii(i, m, c); dumpl(dp[i][m][c]);
  //     }
  //   }
  // }
  long res = -1;
  for(int i = 1; i <= x; ++i) {
    res += dp[i][0][0] + dp[i][0][1] + dp[i][1][1] + dp[i][2][1];
  }
  printf("%ld\n", res);
  
  return 0;
}