pub trait Kitamasa: Clone {
    fn zero() -> Self;
    fn one() -> Self;
    fn add(&self, rhs: &Self) -> Self;
    fn mul(&self, rhs: &Self) -> Self;
}

pub fn kitamasa_kth<T: Kitamasa>(c: &[T], mut k: usize) -> Vec<T> {
    let n = c.len();
    assert!(n > 0);
    let mul = |a: &[T], b: &[T]| -> Vec<T> {
        let mut x = vec![T::zero(); a.len() + b.len() - 1];
        for (i, a) in a.iter().enumerate() {
            for (x, b) in x[i..].iter_mut().zip(b) {
                *x = x.add(&a.mul(b));
            }
        }
        for i in (n..x.len()).rev() {
            let v = x.pop().unwrap();
            for (x, c) in x[(i - n)..].iter_mut().zip(c) {
                *x = x.add(&v.mul(c));
            }
        }
        x
    };
    let mut t = vec![T::one()];
    let mut s = vec![T::zero(), T::one()];
    while k > 0 {
        if k & 1 == 1 {
            t = mul(&t, &s);
        }
        s = mul(&s, &s);
        k >>= 1;
    }
    t.resize(n, T::zero());
    t
}

fn read() -> (usize, Vec<i64>, Vec<i64>) {
    let mut s = String::new();
    use std::io::Read;
    std::io::stdin().read_to_string(&mut s).unwrap();
    let mut it = s.trim().split_whitespace();
    let mut next = || it.next().unwrap().parse::<i64>().unwrap();
    let k = next() as usize;
    let n = next() as usize;
    let a = (0..k).map(|_| next()).collect::<Vec<_>>();
    let b = (0..k).map(|_| next()).collect::<Vec<_>>();
    (n, a, b)
}

impl Kitamasa for i64 {
    fn zero() -> Self {
        std::i64::MIN
    }
    fn one() -> Self {
        std::i64::MAX
    }
    fn add(&self, rhs: &Self) -> Self {
        std::cmp::max(*self, *rhs)
    }
    fn mul(&self, rhs: &Self) -> Self {
        std::cmp::min(*self, *rhs)
    }
}

fn main() {
    let (n, a, b) = read();
    let d = kitamasa_kth(&b, n);
    let ans = a.into_iter().zip(d).fold(std::i64::MIN, |s, p| s.max(p.0.min(p.1)));
    println!("{}", ans);
}