use std::{
    i64::{MAX, MIN},
    io::stdin,
};

fn main() {
    let mut stdin = stdin().lines().map(Result::unwrap);
    let n = stdin.next().unwrap().parse::<usize>().unwrap();
    let a = stdin
        .next()
        .unwrap()
        .split_whitespace()
        .map(|x| x.parse::<i64>().unwrap())
        .collect::<Vec<_>>();
    let mut dp = vec![vec![[MAX, MIN]; n + 1]; n + 1];
    for i in 0..n {
        dp[i][i + 1] = [a[i], a[i]];
    }
    for l in (0..=n).rev() {
        for c in l + 1..n {
            let r = c + 1;
            for x in dp[l][c] {
                assert_ne!(x, MIN);
                assert_ne!(x, MAX);
                for y in dp[c][r] {
                    assert_ne!(y, MIN);
                    assert_ne!(y, MAX);
                    for &z in &[x + y, x - y, x * y] {
                        change_min!(&mut dp[l][r][0], z);
                        change_max!(&mut dp[l][r][1], z);
                    }
                }
            }
        }
    }
    let ans = dp[0][n][1];
    println!("{}", ans);
}

// cmpmore {{{
#[allow(dead_code)]
mod cmpmore {
    pub fn change_min<T: PartialOrd>(lhs: &mut T, rhs: T) {
        if *lhs > rhs {
            *lhs = rhs;
        }
    }
    pub fn change_max<T: PartialOrd>(lhs: &mut T, rhs: T) {
        if *lhs < rhs {
            *lhs = rhs;
        }
    }
    #[macro_export]
    macro_rules! change_min {
        ($lhs:expr, $rhs:expr) => {
            let rhs = $rhs;
            let lhs = $lhs;
            $crate::cmpmore::change_min(lhs, rhs);
        };
    }
    #[macro_export]
    macro_rules! change_max {
        ($lhs:expr, $rhs:expr) => {
            let rhs = $rhs;
            let lhs = $lhs;
            $crate::cmpmore::change_max(lhs, rhs);
        };
    }
    pub trait CmpMore: PartialOrd + Sized {
        fn change_min(&mut self, rhs: Self) {
            change_min(self, rhs)
        }
        fn change_max(&mut self, rhs: Self) {
            change_max(self, rhs)
        }
    }
    impl<T: PartialOrd + Sized> CmpMore for T {}
}
// }}}