#include <iostream>
#include <iomanip>
#include <cmath>
#include <cstdio>
using namespace std;
const double PI = 3.14159265358979323846;
const double eps = 10e-9;
struct pt
{
	double x, y;
	pt(double x = 0, double y = 0) : x(x), y(y) {}
};
double polar_angle(pt a) {
	double d = atan2(a.y, a.x);
	if (d < -eps) d += 2 * PI;
	return d;
}

int main() {
	ios_base::sync_with_stdio(false);
	freopen("angle1.in", "r", stdin);
	freopen("angle1.out", "w", stdout);
	int x, y;
	cin >> x >> y;
	pt a(x, y);
	cout << setprecision(9) << polar_angle(a);
}

/* Tue Mar 13 2018 19:57:31 GMT+0300 (MSK) */