// BOJ 2133

#include <iostream>

using namespace std;

// Function to calculate the number of ways to fill the wall

long long countWaysToFillWall(int N) {

if (N % 2 == 1) {

// If N is odd, there are no ways to fill the wall

return 0;

}

long long dp[N + 1];

// Initialize DP array

dp[0] = 1;

dp[1] = 0;

dp[2] = 3;

// Fill the DP array for each column

for (int i = 4; i <= N; i += 2) {

// Calculate dp[i] based on the number of ways to fill the current section

// dp[i] = dp[i - 2] * 3 (vertical 2×1 tiles) + dp[i - 4] * 2 + dp[i - 2] (horizontal 1×2 tiles)

dp[i] = dp[i - 2] * 3;

for (int j = i - 4; j >= 0; j -= 2) {

dp[i] += dp[j] * 2;

}

}

return dp[N];

}

int main() {

int N;

cin >> N;

// Calculate the number of ways to fill the 3×N wall

long long ways = countWaysToFillWall(N);

// Output the result

cout << ways << endl;

return 0;

}