use std::io::Read;

fn main() {
	let mut s = String::new();
	std::io::stdin().read_to_string(&mut s).ok();
	let v: Vec<u64> = s.split_whitespace().flat_map(str::parse).collect();
	let (n, d) = (v[0] as usize, 1000000007);
	let mut b = v[n + 2..].iter().sum::<u64>();
	println!(
		"{}",
		(1..n + 2)
			.map(|i| {
				let x = b % d * v[i];
				b -= v[v.len() - i];
				x % d
			})
			.sum::<u64>()
			% d
	);
}