import java.io.*; import java.util.*; public class Main { static final int MOD = 1000000007; public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = sc.nextInt(); int[][] dp = new int[n + 5][3]; dp[1][0] = 1; dp[2][1] = 1; dp[3][2] = 1; for (int i = 1; i < n; i++) { for (int j = 0; j < 3; j++) { for (int k = 0; k < 3; k++) { if (j == k) { continue; } dp[i + k + 1][k] += dp[i][j]; dp[i + k + 1][k] %= MOD; } } } int ans = 0; for (int i = 0; i < 3; i++) { ans += dp[n][i]; ans %= MOD; } System.out.println(ans); } } class Scanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); StringBuilder sb = new StringBuilder(); public Scanner() throws Exception { } public int nextInt() throws Exception { return Integer.parseInt(next()); } public long nextLong() throws Exception { return Long.parseLong(next()); } public double nextDouble() throws Exception { return Double.parseDouble(next()); } public String next() throws Exception { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }