[알고리즘] 백준 15610 - Abbey Courtyard (C++)

[문제 링크] : https://www.acmicpc.net/problem/15610

#include <iostream>
#include <cmath>
using namespace std;

double N;

int main(){
    cin >> N;
    cout << fixed;
    cout.precision(8);
    cout << sqrt(N) * 4 << "\n";
    return 0;
}