import java.io.*; import java.util.*; import java.util.stream.*; public class Main { static int[][] dp; static final int MOD = 1000000007; public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = sc.nextInt(); dp = new int[3][n]; int ans = 0; for (int i = 0; i < 3; i++) { ans += dfw(i, n - i - 1); ans %= MOD; } System.out.println(ans); } static int dfw(int idx, int value) { if (value < 0) { return 0; } if (value == 0) { return 1; } if (dp[idx][value] == 0) { for (int i = 0; i < 3; i++) { if (i == idx) { continue; } dp[idx][value] += dfw(i, value - i - 1); dp[idx][value] %= MOD; } } return dp[idx][value]; } } class Utilities { static String arrayToLineString(Object[] arr) { return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n")); } static String arrayToLineString(int[] arr) { return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new)); } } 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 int[] nextIntArray() throws Exception { return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray(); } public String next() throws Exception { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }