import std.algorithm;
import std.array;
import std.container;
import std.conv;
import std.math;
import std.numeric;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

void scan(T...)(ref T a) {
    string[] ss = readln.split;
    foreach (i, t; T) a[i] = ss[i].to!t;
}
T read(T)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readint = read!int;
alias readints = reads!int;

void main() {
    readint;
    auto a = readints;

    int lo = a.reduce!min;
    int hi = a.reduce!max;
    int ans = int.max;
    for (int i = lo; i <= hi; i++) {
        int cost = a.map!(e => (e - i) ^^ 2).sum;
        ans = min(ans, cost);
    }
    writeln(ans);
}
