use proconio::input;

fn main() {
    input! {
        n:usize,
        a:[usize;n],
        b:[usize;n],
    }
    const M: usize = 2000000;

    let mut g = vec![vec![]; M];
    for (&a, &b) in a.iter().zip(b.iter()) {
        g[a].push(a + b);
    }

    let mut dp = vec![false; M];
    dp[1] = true;
    for i in 0..M {
        if !dp[i] {
            continue;
        }

        for &j in g[i].iter() {
            dp[j] = true;
        }
    }

    let ans = dp.iter().rposition(|dpi| *dpi).unwrap();
    println!("{}", ans);
}