use proconio::{fastout, input};

#[fastout]
fn main() {
    input! {
        a: [[i32]],
    }

    println!("{}", output(solve(a)));
}

fn solve(a: Vec<Vec<i32>>) -> Vec<i64> {
    let mut ans = Vec::with_capacity(a.len());
    for a in a {
        let mut minus_max = None;
        let mut minus_min = None;
        let mut plus_max = None;
        let mut plus_min = None;
        let mut zero_flag = false;
        for a in a {
            match a.signum() {
                -1 => {
                    if minus_min == None || minus_min.unwrap() > a {
                        minus_min = Some(a);
                    }
                    if minus_max == None || minus_max.unwrap() < a {
                        minus_max = Some(a);
                    }
                }
                1 => {
                    if plus_min == None || plus_min.unwrap() > a {
                        plus_min = Some(a);
                    }
                    if plus_max == None || plus_max.unwrap() < a {
                        plus_max = Some(a);
                    }
                }
                0 => zero_flag = true,
                _ => (),
            }
        }

        if zero_flag {
            ans.push(0);
        } else if (minus_max == None) && (plus_min != None) {
            ans.push(plus_min.unwrap() as i64 * plus_max.unwrap() as i64);
        } else if (minus_max != None) && (plus_min == None) {
            ans.push(minus_min.unwrap() as i64 * minus_max.unwrap() as i64);
        } else {
            ans.push(minus_max.unwrap() as i64 * plus_min.unwrap() as i64);
        }
    }
    ans
}

fn output(ans: Vec<i64>) -> String {
    ans.into_iter()
        .map(|x| x.to_string())
        .collect::<Vec<_>>()
        .join("\n")
}