use std::io::{stdin, Read};
use std::str::FromStr;
#[allow(unused_imports)]
use std::{cmp, mem, process};
#[allow(unused_imports)]
use std::collections::{HashSet, BTreeMap, BTreeSet};

fn main() {
    let n: usize = read::<usize>();
    let mut dp = vec![vec![0; 4]; 1000105];
    dp[1][1] = 1;
    dp[2][2] = 1;
    dp[3][3] = 1;
    let modulo = 1000000007;
    for i in 1..n + 1 {
        for j in 1..4 {
            for k in 1..4 {
                if k != j {
                    dp[i + j][j] = (dp[i + j][j] + dp[i][k]) % modulo;
                }
            }
        }
    }
    println!("{}", ((dp[n][1] + dp[n][2]) % modulo + dp[n][3]) % modulo);
}


#[allow(dead_code)]
fn read_vec<T: FromStr>(n: usize) -> Vec<T> {
    let mut v = vec![];
    for _ in 0..n {
        let a = read::<T>();
        v.push(a);
    }
    v
}
#[allow(dead_code)]
fn read_str() -> Vec<char> {
    let s: String = read();
    s.chars().collect::<Vec<char>>()
}
#[allow(dead_code)]
fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let stdin = stdin.lock();
    let s = stdin
        .bytes()
        .map(|c| c.unwrap() as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect::<String>();
    s.parse::<T>().unwrap_or_else(
        |_| panic!("Faild to parse {}", s),
    )
}