use proconio::input;

fn cost(target: i32, numbers: &[i32]) -> i32 {
    let mut result = 0;

    for n in numbers {
        result += (target - n) * (target - n)
    }

    result
}

fn main() {
    input!{
        n: i32,
        a: [i32; n],
    };

    let mut min = std::i32::MAX;
    for t in -100..=100 {
        let r = cost(t, &a);
        if r < min {
            min = r;
        }
    }

    println!("{}", {min});
}