process.stdin.resume();
process.stdin.setEncoding('ascii');

var input_stdin = "";
var input_stdin_array = "";
var input_currentline = 0;

process.stdin.on('data', function (data) {
    input_stdin += data;
});
/*
process.on('SIGINT', function(){
    input_stdin_array = input_stdin.split("\n");
    main();
    process.exit();
});
*/
process.stdin.on('end', function () {
    input_stdin_array = input_stdin.split("\n");
    main();    
});

function readLine() {
    return input_stdin_array[input_currentline++];
}

/////////////// ignore above this line ////////////////////


function main() {
	var s = readLine();	
	var N = parseInt(s);
    s = readLine().split(" ");
	for (var i=0; i < N; i++){
		s[i]=parseInt(s[i]);
	}
	
	var ans = 200*200*200+1;
	
	for (var goal = -100; goal <= 100; goal++){
		var cost=0;
		for (var i=0; i < N; i++){
			cost += (s[i]-goal)*(s[i]-goal);
		}
		if (ans > cost){
			ans = cost;
		}
	}
	
	console.log(ans.toString());
}