use std::io::*;

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let n: usize = itr.next().unwrap().parse().unwrap();
    let mut a: Vec<usize> = (0..n)
        .map(|_| itr.next().unwrap().parse().unwrap())
        .collect();

    const MOD: usize = 1_000_000_007;
    for i in 0..n {
        for j in 0..n - i - 1 {
            a[j] = a[j] + a[j + 1];
            a[j] %= MOD;
        }
    }
    println!("{}", a[0]);
}