#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define ld long double
#define pii pair <int, int>
#define sz(a) (int)(a.size())
#define resize(v) v.resize(unique(all(v)) - v.begin());
#define all(a) a.begin(), a.end()
#define forit(it, s) for(__typeof(s.begin()) it = s.begin(); it != s.end(); it ++)

using namespace std;

void Fast_Read_Out()
{
	ios_base::sync_with_stdio(0);
	cin.tie(), cout.tie();
}

void Random()
{
	unsigned int seed;
	asm("rdtsc" : "=A" (seed));
	srand(seed);
}

unsigned int Time()
{
	 unsigned int time = clock() / 1000.00;
	 return time;
}

const int inf = int(1e9) + 123;
const ld pi = acos(-1.0);

struct Point
{
	int x, y;
	Read()
	{
		cin >> x >> y;
	}
	ld Polar_Angle()
	{
		ld alpha = atan2(y, x);
		if(alpha < 0) alpha += 2 * pi;
		return alpha;
	}
}P;

int main ()
{
	freopen("angle1.in", "r", stdin);
	freopen("angle1.out", "w", stdout);
	#ifdef JUDGE
		freopen("input.txt", "r", stdin);
	#endif
	Random();
	Fast_Read_Out();
	P.Read();
	cout << fixed << P.Polar_Angle() << endl;
	#ifdef JUDGE
//		cout << Time() << endl;
	#endif
}
// Easy Peasy Lemon Squeezy