use std::io::*;

fn main() {
	let mut s = 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> = itr.map(|e| e.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]) % MOD;
		}
	}
	
	println!("{}", a[0]);
}