use std::cmp::Ordering; const MOD: usize = 1e9 as usize + 7; fn main() { let mut n = String::new(); std::io::stdin().read_line(&mut n).ok(); let n: usize = n.trim().parse().unwrap(); let mut a = String::new(); std::io::stdin().read_line(&mut a).ok(); let a: Vec = a.trim().split_whitespace().map(|s| s.parse().unwrap()).collect(); let mut b = String::new(); std::io::stdin().read_line(&mut b).ok(); let b: Vec = b.trim().split_whitespace().map(|s| s.parse().unwrap()).collect(); let mut orders = (0..n).collect::>(); orders.sort_by(|&left, &right| { let lrval = a[left] + b[left] * a[right]; let rlval = a[right] + b[right] * a[left]; if lrval > rlval { Ordering::Less } else { Ordering::Greater } }); let mut level = 1usize; let mut result = 0usize; for &i in orders.iter() { result += level * a[i]; result %= MOD; level *= b[i]; level %= MOD; } println!("{}", result); }