#include <string>
#include <iostream>
#include <vector>

using namespace std;

using ll = long long;

int main() {
	vector<ll> arr(10000);
	for (int i = 0, x = 2020; i < arr.size(); ++i, ++x)
		arr[i] = x * x;
	
	ll minn = 1e18;
	for (int i = 0; i < arr.size(); ++i) {
		for (int j = i + 1; j < arr.size(); ++j) {
			if (arr[j] == arr[i] * 2 - 2019 * 2019)
				minn = min(minn, i + 2020LL * 2LL + j);
		}
	}
	cout << minn; 
	return 0;
}