#![allow(unused_imports)]
use std::io::{ self, Write };
use std::str::FromStr;
use std::cmp::{ min, max };
use std::collections::{ BinaryHeap, VecDeque };

#[allow(unused_macros)]
macro_rules! trace {
    ($var:expr) => ({
        let _ = writeln!(&mut std::io::stderr(), ">>> {} = {:?}", stringify!($var), $var);
    })
}
#[allow(unused_macros)]
macro_rules! swap { ($a:expr, $b:expr) => ({ let t = $b; $b = $a; $a = t; }) }

const M: usize = 1_000_000_007;

fn main() {
    let mut sc = Scanner::new();
    let n: usize = sc.cin();
    let mut dp = vec![vec![0; 3]; n + 8];

    // for k in 0..3 { dp[0][k] = 1; }
    for i in 0..(n + 1) {
        for k in 0..3 {
            if i == 0 {
                dp[i + k + 1][k] += 1;
            } else {
                dp[i + k + 1][k] += dp[i][(k + 1) % 3] + dp[i][(k + 2) % 3];
            }
            dp[i + k + 1][k] %= M;
        }
    }
    let ans = (dp[n][0] + dp[n][1] + dp[n][2]) % M;
    println!("{}", ans);
}

#[allow(dead_code)]
struct Scanner { stdin: io::Stdin, buffer: VecDeque<String>, }
#[allow(dead_code)]
impl Scanner {
    fn new() -> Scanner { Scanner { stdin: io::stdin(), buffer: VecDeque::new() } }
    fn reserve(&mut self) {
        while self.buffer.len() == 0 {
            let mut line = String::new();
            let _ = self.stdin.read_line(&mut line);
            for w in line.split_whitespace() {
                self.buffer.push_back(String::from(w));
            }
        }
    }
    fn cin<T: FromStr>(&mut self) -> T {
        self.reserve();
        match self.buffer.pop_front().unwrap().parse::<T>() {
            Ok(a) => a,
            Err(_) => panic!("parse err")
        }
    }
    fn get_char(&mut self) -> char {
        self.reserve();
        let head = self.buffer[0].chars().nth(0).unwrap();
        let tail = String::from( &self.buffer[0][1..] );
        if tail.len()>0 { self.buffer[0]=tail } else { self.buffer.pop_front(); }
        head
    }
}