fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let n: usize = n.trim().parse().unwrap();

    const DIVISOR: usize = 1_000_000_007;
    let mut ken1: Vec<usize> = vec![0; n];
    let mut ken2: Vec<usize> = vec![0; n];
    let mut pa: Vec<usize> = vec![0; n];
    ken1[0] = 1;
    for i in 1..n {
        ken2[i] += ken1[i-1];
        ken1[i] += pa[i-1];
        pa[i] += ken1[i-1] + ken2[i-1];
        ken2[i] %= DIVISOR;
        ken1[i] %= DIVISOR;
        pa[i] %= DIVISOR;
    }
    println!("{}", (ken1[n-1] + ken2[n-1] + pa[n-1]) % DIVISOR);
}